Weapons

1. Blaster: The only advantage to this weapon is that it has infinite ammo. Otherwise, the weapon is extremely weak and the projectile it shoots very slow. It's very useful, however, as a make-shift flashlight; if you are in a dark area, fire a few Blaster shots to light up the room.
2. Shotgun: It's substantially better than the Blaster and is not too bad at long range. However, it's totally outclassed by the Super Shotgun and there are far better long range weapons
3. Super Shotgun: With some skill, you can take on just about any enemy easily with the Super Shotgun save for bosses and Tanks. It does massive damage if you hit an enemy with the entire spread and often inflicts hitstun on an enemy, setting them up for more damage. It's only weakness es are that it's a poor long range weapon and that it's not ideal against crowds or enemies coming from different angles.
4. Machine Gun: This will be one of the better long range weapons you will get early in the game. The gun bucks around a bit when first fired, so ease the aim after firing the initial burst. It's surprisingly powerful for its size and is excellent for getting rid of flying enemies in a hurry.
5. Chaingun: A somewhat-upgrade to the Machine Gun. It does colossal damage and can kill anything in a hurry. Perfect against crowds and sudden ambushes. Against flying enemies, you'll still want to use the Machine Gun. It also has a slow start-up and uses up ammo very quickly.
6. Grenades: These can be hurled around corners and over cliffs, and can be cooked by holding down the fire button, so that they detonate sooner after being thrown. They aren't very effective overall; if possible, use the Grenade Launcher instead.
7. Grenade Launcher: A much-better option for your grenades. It shoots them pretty far and accurate. It's perfect for disposing of tough enemies from safety behind corners and below you under ledges.
8. Hyperblaster: This weapon can kill enemies faster than any other. However, it uses up ammo extremely quickly. If you need to storm an area with a lot of tough enemies, this will be your weapon; just make sure to aim for their feet so that they don't duck the shots.
9. Rocket Launcher: It shoots a dumb missile that explodes. The projectile is not particularly fast or strong, and it has no special uses unlike the BFG10K, Rail Gun, or Grenade Launcher. It's biggest advantage is the fast firing rate, making it the best anti-crowd weapon amongst the upper tier weapons. It's also very handy for "rocket jumping" (using the explosion force from rockets to launch your character into the air).
10. Rail Gun: It shoots a laser that instantly hits its target with perfect accuracy. This is an excellent weapon to pick off strong enemies and tough targets at a distance with. There are also enemies that are directly weak to it, such as Brains and Icarus. Excellent weapon, with the only drawback being the bad firing rate.
11. BFG10K: It uses the same ammo as the Hyperblaster. It fires a giant green ball that explodes, destroying all in it's path. Use this to kill bosses easily.

Items

1. First Aid: Restores 10 health.
2. Medkit: Restores 25 health.
3. Megahealth: Restores 100 health; can break the 100-point health limit to a maximum of 200 points
4. Stimpacks: Restores 1 health; can break the 100-point health limit to a maximum of 200 points.
5. Adrenaline: Replenishes health to the maximum amount.
6. Armor Shard: Adds 1 point to your Armor rating.
7. Jacket Armor: Adds 25 points to your Armor rating.
8. Combat Armor: Adds 100 points to your Armor rating.
9. Body Armor: Adds 200 points to your Armor rating.
10. Power Suit: Allows ammo for the Hyperblaster/BFG10K to double as Armor points.
11. Silencer: Turns off firing sound effects for all weapons for a limited time.
12. Rebreather: Allows you to breath underwater for a limited time.
13. Environment Suit: Allows you to swim and breath in toxic waste for a limited time.
14. Invincibility: Makes you temporarily invincible to all damage for a limited time.
15. Quad Damage: All your weapons do four times as much damage for a limited time.
16. Bandolier: Increases the maximum amount of ammo you can carry.
17. Ammo Pack: Further increases the maximum amount of ammo you can carry.

1. Red Light Guards: These are the weakest enemies in the game, and wield Blaster pistols. They are not a threat and any weapon will work. Watch out for their death animations where they try to fire a few parting shots.
2. Green Light Guards: A tougher variant; these use Shotguns instead. Blast them with your own Shotgun. The Super Shotgun can drop multiple at once.
3. Grey Light Guards: These are the toughest Guards and use Machine Guns. Take them out with Shotguns/Super Shotguns and use Machine Guns at long range.
4. Enforcers: These thugs wield Machine Guns and can take more damage than Light Guards. They are weak to the Shotguns at close range, but at long range, you'll need the Machine Gun or better to get rid of them quickly. If you decapitate them, look out for their final shooting attack.
5. Gunners: These elite troops have Machine Guns and can fire grenades. Their grenade salvos are extremely damaging, often fatal if you are caught up in one. They can take a lot of punishment. At close range, a Super Shotgun can stun one, and down it in two shots. At longer ranges, you'll need to rely on grenades and Machine Guns. If there are multiple, use the Rocket Launcher, Hyperblaster or Chaingun immediately or they will probably bury you in grenades. If they attack, try to circle strafe them as best you can.
6. Parasites: Dangerous dog-like Strogg fighters. They have a prehensile tongue they use to leech energy off of you. For their size, they take a lot of damage to defeat. Fortunately, they are extremely weak to the Super Shotgun; one hit sends them sprawling, allowing you to easily finish them with another shot.
7. Berserkers: These towering fighters have no firearms. They simply chase after you and try to pulverize you with their arms. Their attacks can throw you a great distance. Blow them down with the Super Shotgun. Their attacks are easy to dodge if you are concentrating; you can bait them into attacking, then simply step back and let them whiff while you shoot them.
8. Gladiators: Mechanized warriors armed with a claw and a Rail Gun. You can actually dodge their melee attacks in the same way as the Berserkers. You can even dodge the Rail Gun repeatedly by simply sidestepping back and forth; the Gladiators are really bad at leading their targets. The Gladiator is tough enough to survive as many as five direct hits with the Super Shotgun.
9. Tanks: Slow-moving hulks armed with a Chaingun and damaging explosive artillery. Their attacks are not easy to dodge, however, they are slow and often get stuck walking around corners. Pound on them with grenades and rockets from behind cover. If you are forced to fight one out in the open, use the Chaingun or Hyperblaster to kill it quickly.
10. Flyers: Flying skiff-like machines that pester with blaster shots. Use the Machine Gun or Shotgun to pick them off out of the sky before they do too much damage.
11. Icarus: Similar to Flyers, except more humanoid and much tougher and dangerous. Use the Chaingun or Hyperblaster to get rid of them quickly before they can get organized.
12. Barracuda Sharks: Freakish fish that swim about in some waters. Since all guns work fine underwater and their stamina and attack damage is low, they are no threat; use the Shotgun or Machine Gun.
13. Mutant: Mutoid monsters that attack similarly to the Parasite. The differences are that they are faster, can take more damage, and have a highly-damaging flying leap. The Super Shotgun will cancel all their attacks and kill them in about 3 direct hits.
14. Medic: These resemble the Gladiators, except that their firepower is much weaker and they can revive dead enemies. They cannot revive enemies who's corpses have been "gibbed" (blown to pieces), so if some are in the area, shoot the corpses to keep the Medics from doing their jobs.
15. Technician: These floating red tubes fly about, usually minding their own business. They tend to attack only when threatened or if you get too close. They aren't too dangerous although they are tough enough to survive a direct Super Shotgun blast.
16. Iron Maidens: Cyborg females that fire rockets. They are dangerous if they take you by surprise, but otherwise they are not too dangerous; they're slow, have a poor firing ratem and telegraph their attacks by making loud hissing noises. Use the Rail Gun or Rocket Launcher for easy kills.
17. Brains: Bizarre freaks that slither around very slowly but hit with an incredibly damaging melee attack. They also have a forcefield that protects them from the front, greatly reducing the damage they take from frontal attacks. However, the forcefield is easily neutralized by either flanking or attack them from behind, or simply shooting through it with the Rail Gun. Just don't let them get too close.

Mission 1

Outer Base

1. From the start, walk down the hall and crawl into the hole in the wall on the left.
2. Crawl through the next hole beyond to grab a Jacket Armor.
3. On the other side, follow the path around the bend into a blasted-open hole in the wall.
4. Climb the rubble to enter the hole in the wall. Kill all the enemies and grab the Shotgun, then return back to the hall you originally started from.
5. In your original hallway, look for a plate glass window and shoot it. Drop down through the window.
6. Follow the path down below to another crawl space. Follow the crawl space into a flooded area.
7. Outer Base Secret #1: From the crawl space exit into the flooded area, swim straight ahead, diving under the wall. Pick up the grenades by the corpse.
8. Follow the water till it exits into a gulch. Kill all the enemies and grab the box of shells. Take the stairs to exit.
9. Outer Base Secret #2: Crawl underneath the stairs for a Silencer.
10. You can go left to return to the first hallway and get more supplies, otherwise, turn right and follow the path.
11. Kill all the enemies in the next room with the Shotgun, then go up the stairs onto the elevator to exit. Don't forget the two boxes of shells below the elevator.
12. Outer Base Secret #3: Before riding the elevator out, go underneath the stairs and shoot the glowing orange trick button on the ceiling. It will open a secret compartment with medkits and some grenades.

Installation

1. Get the Shotgun out if it's not already equipped and blast everything that moves in the cargo bay ahead. Watch for soldiers from above.
2. Go down the next corridor and press the button to open a secret panel revealing a Machine Gun. Watch out for enemies spawning from behind after you take it.
3. Continue fighting down the hall into the next room and take the elevator up.
4. Up top, you may fight down the hallways to get above the cargo room. There's plenty of enemies to kill, including some that appear when you collect items. Otherwise, take the other exit out to the main bridge.
5. Kill all in your way as you drop down into the moat. Go to the right and enter the sewer tunnel.
6. Installation Secret #1: Before going into the sewer tunnel, look for a crawl space to the left of the tunnel and enter. Hug the wall on your rightside till you find a crack in the wall. Shoot it down and grab the Shotgun.
7. Kill everything inside the sewer tunnel, then press the button to open the sewer access. Drop down it.

Lost Station

1. Although you are now technically in the Comm Center, you can access the secret level "Lost Station" right at the start of this level. For now, you can swim underneath the grate for some grenades. Otherwise, fight your way into the next room.
2. Kill everything in sight, then collect the goodies. Dive into the water to follow the path to Lost Station.
3. Comm Center Secret #1 and #2: You get two for the price of one. Swim underneath the stairs going into the hole. Look for a very tiny crawlspace right near your left and enter it. Surface, then take the elevator to begin the secret level "Lost Station", which also counts as a secret.
4. Once inside the Lost Station, follow the linear path to the first tram cart, shotgunning all in your way. Ignore the sealed hatch door.
5. When you reach the tram cart, ignore it and go right. Kill the enemies and search the crates for a Machine Gun.
6. Lost Station Secret #1: Climb the smallest crate on the floor and use it to jump up to the crate next to it. Jump to the crates on the opposite side and climb over them to find a Silencer.
7. Lost Station Secret #2: Dive into the water underneath the tram cart. Swim to the end of a tunnel to collect some goodies and open the sealed hatch you passed earlier. Watch out for a sneak attack from a Mutant.
8. Hop on the tram cart and when it hits the chute ahead and travels upwards, climb onto the lip and crouch-walk into the wall. Your character should slip into a crevice with some health.
9. Drop down from the crevice into the water below. Shotgun the Barracuda Sharks and look for a submerged lift in a nearby tunnel you can ride.
10. Lost Station Secret #3: After riding the lift out of the water-filled tunnel, follow the path to another pool. You'll automatically get this secret. Watch out for the Parasite here.
11. After getting Secret #3, follow the path of watery tunnels to surface out by the second tram cart station. Kill the Enforcers. You can also continue to explore the pools for more goodies; watch out for sharks.
12. Climb up the station and enter the door. Go up the stairs and kill the enemies. Turn around, facing towards the bottom of the stairway and shoot the trick button above the stairs. It will raise a ramp; follow it to the Red Key and collect it.
13. Lost Station Secret #4: Before raising the ramp, stand near the trick button and shoot it, then move forward before the ramp can raise up. Go underneath the ramp for the secret; use the button here to keep the ramp from descending and crushing you.
14. Carefully follow the corridor into an area full of Light Guards and Enforcers. Ignore the pair of Enforcers above you at the start and instead blast your way through the tunnel killing all in your path, looping around to the pair's position. Take them out.
15. Lost Station Secret #5: Over by the two Enforcers is a trick button you can shoot, above three cannons that will trigger if you approach them. Shooting the trick button deactivates the cannon trap and opens a secret passage. Explore it to get the secret.
16. Continue following the passage past the battle into a new tunnel. Kill all in your way as you travel into an area with a giant water pump.
17. The area with the pump will have loads of enemies, including Flyers. Drop them all with the Machine Gun, then go down and ride the elevator up to the top of the pump.
18. Lost Station Secret #6: Before riding up the elevator, swim underwater and shoot the loose stone plating underneath the pump structure. Swim in, surface in the lagoon inside, and collect the goodies, including Invincibility.
19. Atop the pump, press on the console to lower a scaffold to reach a room. Enter it, kill the enemies, then collect the Super Shotgun and the mission objective.
20. Return to the elevator at the start of this level to exit Lost Station. There will be loads of Flyers and other enemies along the way, so tread carefully.

Comm Center

1. Back at the Comm Center, enter the room past the pool you exited and get ready to fight several enemies, including two Parasites. Shoot them all long range with the Machine Gun.
2. Go up to the second floor of this room and collect the Quad Damage on the crates before leaving.
3. Continue shooting your way to a room with a pit filled with toxic waste. Ignore the pit and continue on to the courtyard outside.
4. Can't open the locked door in the courtyard without the Blue Key, so kill your way into the nearby room with the black-and-yellow striped crates. These crates are booby-trapped, exploding when the alarm button is triggered by an enemy. Take them all out from the doorway with the Machine Gun.
5. Ride the elevator up and follow the catwalk ahead, shooting down all in your path.
6. When the catwalk turns, you can drop down onto the crates by the toxic waste pit to grab an Environmental Suit. With this item, you can drop into the pit to grab Adrenaline, then hit the switch to flood the pit with toxic waste to swim out of the pit. However, none of this counts as a secret, so save the suit unless you are desperate for health.
7. The path leads to a corridor with a glass window. Kill all the enemies lurking, then shoot through the glass and waste the Gunner. His grenades can't reach you from your position.
8. Enter the Gunner's room. With him dead, you can use the console to give you the Blue Key.
9. Fight your way back to the locked door and open it with the Blue Key. Waste all inside and ride the elevator up to the second floor.
10. Exit the Comm Center to the rear end of Installation.
11. Once inside the Installation, throw the lever to open the level exit, then follow the path back to the broken bridge.
12. Go around inside and waste all in your path to enter the door to the final area.
13. The exit elevator is guarded by two Gunners, the second of which will appear after hitting the button to open the exit. Kill them with grenades or the Super Shotgun.
14. Installation Secret #2: After killing the Gunners, go past them down the ramp into a basement area. Search around the nooks until you find a pile of goodies by a corpse. Watch out for Light Guards on the way back out.
15. Ride the elevator out of the level.

Mission 2

Ammo Depot

1. Battle your way through the area with the lifts and clear the room. If you fall down, use the console switches to ride back up.
2. Ammo Depot Secret #1: In the room with the lifts, look for a trick button on the ceiling corner. Shoot it to open a secret panel holding a Quad Damage.
3. Fight your way through the next room. Watch out the Techinician and for Enforcers ambushing through a secret panel.
4. In the next room, kill the enemies above and below, then drop down and hit the console switches. Ride the bottom lift back up, then use the now-lowered lift on the second floor to ride up to the catwalk above.
5. Hit the switch on the topmost catwalk to raise a bridge to the exit door, then access it. Watch out for a Berserker barreling through on the other side.
6. Battle into the next area. Kill everyone lurking around the crates until everyone is dead; look out for Berserkers attacking from behind.
7. Once all the enemies are dead, shoot the trick button behind the forcefield from the area with the crates. With the forcefield lowered, throw the switch to send the ammo cargo into the nearby wall, blowing open an escape route.
8. Ammo Depot Secret #2: There's a second switch by the one used to move the ammo cargo. Hit it to open a nearby secret staircase. Kill the Enforcer and grab the goodies he guards.
9. Enter the blown-open passage and follow the corridor to the next area. Watch out for Light Guards hiding behind crates.
10. In the next area, blow away all the troops on your level, then grenade the goons below until it is safe to drop down.
11. Follow the linear path through the corridors and freight lifts, checking carefully around corners and shotgunning anything that moves. You can throw the switch in the room with the suspended crates to crush some goons below.
12. The path leads to a bridge suspended over lava. Cross it and kill the Light Guards beyond to enter a flooded depot.
13. Ammo Depot Secret #3: There is a switch in the lava room that will lower the bridge. This will allow you to reach a secret passage underneath the other side of the bridge that leads to a Chaingun.
14. In the flooded depot, swim through the open door and kill all the enemies guarding the platforms. Use the crates to reach the platform with the switch and throw it, then cross to the now-open door on the other side.
15. Fight your way through the corridors to a lift and ride it up. Follow it to a catwalk that leads high above the door you raised the bridge to reach.
16. On the other side of the catwalk, press the button to open the ladder hatch for a shortcut back to the start of the level, then continue on.
17. The Warehouse is inaccessible as you need a Power Cube, so make a left at the fork in the catwalk ahead to go to the Supply Station.

Supply Station

1. Kill the Light Grunts and the Gunner with the Chaingun, then continue onward. If you fall into the ravine, use the lift below to climb back up.
2. Supply Station Secret #1: Drop into the ravine and face the lift that takes you back up. Go left and press against the greyish metal plating to open up a secret passage to Combat Armor.
3. Go into the cargo room and shoot everyone in there. Climb up the crates and hit the switch to drop a crate on the Berserker, then exit through the only unlocked door.
4. Supply Station Secret #2: Climb onto the crates and use them to jump onto the big crate sliding in and out of the passage in the wall. Crouch to squeeze into the passage it constantly exits and enters from and collect the Quad Damage you find in there.
5. In the room ahead, pop all the snipers on the stacks of crates above. You can climb the crates and jump onto the ring of crates ahead for a Chaingun, but watch out for a Berserker and Gunner ambushing you when you collect it.
6. Ride the lift up and take the first Power Cube. This will drop the laser beams, allowing you to enter the next area.
7. Continue on till you see another sliding crate. It's deactivated, so hit the switch to get it to move, then follow it through a door.
8. Hit the switch on the other side to keep the exit door back open, then drop down on to the conveyor to reach the train station.
9. Kill all the enemies here, then use the train to cross to the other side of the tracks. Hit the switch here to wreck the train, then grab the Power Cube to disable the tracks.
10. Drop onto the tracks and hit the switch underneath the rails, then climb the ladder upward.
11. In the next area, watch out for Light Guards and a Gunner, and use another ladder to climb up to their area. You will now be entering a crate maze.
12. Supply Station Secret #3: Enter the crate maze and hang left. In one of the dead ends is a crate that is a unique olive color. Shoot it and grab the medkit inside.
13. Search through the crate maze for a switch and hit it to open a panel in the floor. Take the stairs down.
14. Collect the supplies, then ride the lift down to another cargo bay.
15. Kill all the enemies, then climb the ladder and hit the switch to get the crane to move. Ride the crane up to the next area.
16. Enter the door ahead and grab the Power Cube, then enter the crate depot. Shoot all the enemies (watch the Gunner), then climb the ladder and hit the switch to open an exit.
17. Follow the path. It will lead back to the entrance of this level; you'll need to return to the Ammo Depot to drop off your Power Cubes.
18. In the Ammo Depot go across the catwalk to the other side and press against the circuit panel inside the next room. It will open and you will use one of your Power Cubes on the circuit board inside.
19. Now you can operate the nearby lift. Use it to ride it to the exit, leading into the Warehouse.

Warehouse

1. Follow the path, ignoring the dark areas for now. At the end of the path is another circuit board for your Power Cubes.
2. With the power restored, backtrack to kill any encroaching enemies and collect a few extra items, then ride the lift up to head to the next area.
3. The next area will have a vicious battle. From the top of the steps, gun down the Light Guards and use the Super Shotgun to take out the Parasites. After winning, progress to the next area, ignoring the conveyor belt for now.
4. More Parasites and Berserkers in the next room, so be careful. Once they are all dead, use another Power Cube on the circuit board to operate a lift back to the conveyor belt room.
5. The conveyor is now operating, so ride it to a small storage area. Kill the goons inside, then hit the switch to open a door and lower a lift. Ride it upwards.
6. Kill the parasite, then enter the next area. Find the Gunner on the other side of the catwalk, past the conveyor, and kill him first if possible. Then jump onto the crates and kill the other enemies.
7. Drop down and use a Power Cube to start the conveyor and two lifts you can use to reach it.
8. On the other side of the conveyor, a crate will lower, dropping off a small explosive box. Shoot the box to blow open the locked door.
9. Hit the switch inside to open the spiral staircase and battle your way down.
10. Warehouse Secret #1: At the very bottom of the spiral staircase is a stack of crates. Behind them is a trick button; it's very hard to see, let alone hit, but if you can, it will open another set of spiral stairs going downward, leading to a huge stash of goodies.
11. Enter the next room and hit the switch you see coming in. It will unleash a Tank; take him out with grenades as he slowly waddles out of his little nook. Once he is dead, press against the console keyboard he was guarding.
12. The console keyboard opens access to a cargo bay. Kill all the enemies on both ends of the gap and below, then go to the left and hit the switch in the control room to activate two lifts. You can use the lifts to cross the gap, or just hop across using the crates.
13. Warehouse Secret #2: Shoot the trick button on the ceiling above the lift switch. It will trigger a ladder and hatch, allowing you to grab a Quad Damage.
14. On the other side of the gap, enter the final room and hit the EXIT switch, then ride the conveyor out of the level.

Mission 3

Main Gate

1. This level will have a ton of tough baddies and Flyers, so be vigilant. Kill all the enemies in the starting room and outside on the bridge.
2. Dive off of the bridge here and find a tunnel to swim down. Watch out for Flyers. If you need to get back up, use the lift below, tucked in a small nook with a corpse.
3. Main Gate Secret #1: The lift and the goodies around the corpse count as a secret.
4. Swim along, blasting all in your path, through a sewage tunnel. It will end into reservoir.
5. Don't swim through the spinning fan below. Instead, surface and shoot the red laser beam device through the bars. If the Gunner inside hits the alarm switch, another one will spawn from behind you, so be careful.
6. By destroying the beam device, the fans will deactivate. Dive in and swim through the fans, surfacing on the other end by the beam device.
7. Follow the corridors to a ladder sealed by a grate. Shoot the grate and climb out.
8. Use the circular lift right in front of you to get on the balcony. Stand on the button pad, then snipe the enemy on the turret.
9. Climb down and get ready for a big battle with Flyers and a Gladiator in the area with the turret.
10. You can end this level right now if you wish, or you can enter where the Gladiator came from and fight your way back through the earlier section of the base you skipped via your swim off the bridge. There's loads of enemies to kill and a secret to gain. Note that the yellow-ish scanner devices will create a laser grid that you will need to hopscotch through if you intend to backtrack, and there will be deadly red trap beams blocking your path past them. To get past the trap beams, you'll need to push the explosive barrel by them and use it to jump over them. If the barrel is destroyed, you'll need to backtrack all the way through the sewage line back up the bridge to go around those beams.
11. Main Gate Secret #2: Near the red beams, on the side of the area closer to the bridge, is an alarm switch guarded by loads of Gunners and Berserkers. When you press it, a secret panel will blow open; use the computers to climb into the newly-opened duct for Combat Armor.
12. When ready, take the elevator by the turret to head to the Detention Center.

Detention Center

1. Collect the supplies in front of you, then go around the back and kill the slew of Enforcers and Gunners.
2. Past them outside is a Tank; you can trick his AI into wandering into the doorway by simply retreating out of the corridor. This gets him stuck, letting you kill him easily with grenades.
3. Dive off the bridge the Tank was patrolling and get the armor, then follow the river towards the other side.
4. You can now sneak up on the Gladiator and easily whack him with the Chaingun. If he reaches the alarm, Flyers will appear to aid him (you can press the alarm yourself if you want to increase your kill count).
5. Grab the Blue Key and use it to open the vault door the Tank was guarding.
6. Inside the prison entrance, kill the Berserkers and take the lift up. Kill the Gladiator on the otherside with the Chaingun, then do the same to the Gunner right below you.
7. Collect any supplies and enter the detention center proper. Note the locked door before you go; you'll need the Red Key to open it.
8. Once inside, get the Chaingun out and book right until you hit the big grate with the prisoners below, then go up the stairs. Slaughter everything in your way. There are Medics running around in here, whom can revive dead Strogg unless they've been gibbed by the Chaingun. Watch out for a Gunner right behind you on a ledge on the stairs. He's guarding a trick button you can shoot to raise the staircase up to his ledge for some ammo.
9. Detention Center Secret #1: Shoot the trick button the Gunner is guarding and quickly move underneath his platform before the staircase raises. Grab the secret underneath the raised stairs before it lowers.
10. After clearing this area, take out the enemies guarding the cell block below. The Quad Damage guarded by the red laser traps can be accessed by pressing the button on the console near the big grate; you may need it in a second. If you wish, you can open the cells for some ammo (including rockets) and mercy-kill the prisoners for free ammo.
11. Head into the next area; there's loads of Medics and a Tank, so it might be a good idea to use Quad Damage and the Chaingun to wipe them out.
12. Detention Center Secret #2: Kill all the enemies first, then from the cell block, go towards the area with the Tanks and Medics and hit the button on the wall. Quickly run to the right, hugging the wall on your left, skipping the first door, and at the second door, stop and hit the button next to it. Go inside that door and hit the button on the other side, then go back to the first door you skipped and quickly grab the goodies inside. You must do this all in one quick motion or otherwise the various doors and locks will reset, forcing you to start over.
13. Open the door the Tank was guarding to enter the Security Complex.

Security Complex

1. Blast the enemies outside in the courtyard, then enter the door straight ahead from where you enter.
2. Security Complex Secret #1: Go into the door on your left and search for two grenades lying side by side near some yellow laser traps. Shoot the wall panel they are lying in front of to open a secret panel, giving you a Grenade Launcher
3. There will be loads of Gladiators, Medics, and Gunners here. Try to gib the Gunners from long range with the Chaingun or Grenade Launcher from the doorway, Super Shotgunning anything trying to storm your position.
4. Once they're all dead, go up to the Gunner's catwalk and follow it around to a Gladiator guarding a Red Key. Kill him and take the key. Take note of the pyramid outside; you'll be returning here later.
5. Return to the Detention Center and open the locked door by the prison entrance with the Red Key. Go inside and mow down the Parasites with the Super Shotgun.
6. Kill all the Enforcers in the wide-open area, then open the door and go left to go to the upper floor for some supplies.
7. Continue down the main corridor and get ready for a big Parasite/Enforcer battle. Keep going past them into the area with the Gladiator you killed way back.
8. Now you can activate the console to shut down the yellow trap lasers throughout this mission. Do so.
9. Return to the Security Complex and take the door to the left of the entrance. Fight your way into the Guard House (watch out for the Tank lurking above in the courtyard entrance.

Guard House

1. Kill the guards and the Gunner above. Execute the prisoners if you like for supplies.
2. Ride up the lift and follow the linear path, killing the Enforcers in your way.
3. Guard House Secret #1: Shoot the explosive barrels in the area with the Enforcers; they will blow open a secret passage (or you can do it yourself with grenades if they somehow fail to).
4. The path ends into a pavilion with two small ramps, and two water-logged exits below. Watch out for a Mutant busting through the wall if you go up the left ramp.
5. Guard House Secret #2: Right when you enter this area, you should see a brick sticking out of the wall ahead, in between the two ramps. Press it; the left ramp will lower, giving you access to Adrenaline.
6. Don't drop down into the watery area below; instead go into the door ahead and blast all the Mutants and Guards you find along and below the catwalk in the next area. After securing this area, take the door the catwalk leads into.
7. Follow the path, blasting the Guards, and you should see a Hyperblaster sitting out in the open past them. Save the game before picking it up as doing so unleashes a floor trap.
8. Past the Hyperblaster is the watery area from earlier. You can dive in the water for a medkit, or explore the other exit for some supplies and a secret. Otherwise, return to the previous room with the catwalk and explore the stairs leading down.
9. Guard House Secret #3: Go in the other exit across the water and once inside, crawl through the hole in the locked door to get the secret and a Grenade Launcher in the lava-filled room.
10. Follow the bridge to the area outside. Kill the Tank and his helpers with the Hyperblaster, then hit the switch he's guarding to lower a forcefield blocking access to the bunker. If you wish, you can go down the steps and search around to find a Power Shield.
11. Go inside the bunker you've opened access to and kill all the enemies, then take the Pyramid Key.
12. Return to the Security Complex.

Torture Chamber

1. Don't bother going to the pyramid yet. Instead, go into the central area of the Security Complex and take the only other route you haven't gone down yet: the rocky tunnel.
2. Kill the Tank down the tunnel with grenades and hit the switch to raise the bridge. This summons two Icarus; kill them with the Chaingun or Hyperblaster.
3. Press onward into a room with two Gunners torturing some prisoners along with a Tank. Use the Hyperblaster to storm the Gunner's position, then take the Tank from there.
4. Enter the Torture Chamber proper. It's best to have the Hyperblaster out for this area at all times as there's plenty of Gunners and Tanks in tight places here.
5. At the beginning of this area, kill the Tank, then step on the button pad to operate the lift leading into the torture chambers themselves.
6. Torture Chamber Secret #1: Don't go down the lift yet. Instead, go outside and around to the right, picking up the Hyperblaster and ammo.
7. Ride the lift down while facing the button pad and go straight, following the path without dropping down to the floors below. The area looks complex, but it's really a tiered ring of paths. You know you are going the right way when you pass through a room with a torture victim below a buzzsaw.
8. A bit past the room with the buzzsaw, you will come across a Data CD in a small nook; take it. If the enemies reach the console next to it, it will be momentarily sealed off by a forcefield.
9. Continue forward along your catwalk from the Data CD. You should see text on the wall pointing towards "CELL BLOCK B", and a door nearby. Use the console nearby the door to open it and go into Cell Block B.
10. Torture Chamber Secret #2: Before going into Cell Block B, go down the stairs and enter the row of cells for Cell Block A. Open the cell beneath the text "CELL BLOCK A" and shoot the bricks of the wall where it meets the floor. Crawl in for Invincibility.
11. Kill the Tank, then drop down and kill the guards. You can go forward to kill some more troops if you like, but your real goal is to open the cell with the hole in the floor and drop down.
12. Kill the Parasite, and collect the Rebreather and use it (or one of your own if you have one). Find and open the water main access and swim along it to another torture chamber.
13. Kill the guards in the crucifix torture chamber and take the Security Pass.
14. Blast your way out and follow the path. You should hit another torture chamber: a prisoner held over a cage above a lava pit. The exit is nearby, marked with a sign. Take it to leave.
15. Torture Chamber Secret #3: It's in the same lava pit the prisoner is lowered into. You'll need Invincibility to dive into the pit to reach it safely. Use the nearby lift to get back out.
16. The exit leads you back to the Security Complex. Follow the path and it should lead you right to the same bunker where the pyramid is located, on the highest catwalk. Drop down and unlock the pyramid.
17. Kill the Icarus that comes out of the pyramid, then continue on to the Grid Complex.

Grid Complex

1. Progress through the complex; be careful of the flickering blue lasers. You can slip past some of them for power-ups.
2. To get past the blue lasers surrounding the central structure, crawl under the leftmost ones. Ride up the lift past them.
3. Outside are two Tanks; kill them. This unleashes the boss, a "Tank Commander". Kill the Berserkers first before dealing with him.
4. The Tank Commander is simple; hide around a corner and blast any part of him that's visible with the Hyperblaster. He'll often get stuck on corners and shoot his rockets into the walls, damaging himself further in the process. Once he's dead, climb down the ladder nearby where he originated.
5. Down below, go around the blue column of light and step on the lift. Hit the nearby button and quickly shoot the blue crystal that appears before the lasers can kill you.
6. Once it's destroyed, a forcefield nearby will deactivate, allowing you to exit the level.

Mission 4

Mine Entrance

1. Head out into the lava-filled outside. Kill everything outside, collecting ammo and any guns you need.
2. Follow the tunnel into the next lava area. Clear it of enemies, then jump to the platform below to the left of the catwalk.
3. Mine Entrance Secret #1: Before jumping down, look around for one of the red-colored circuit panels in this area to have a blinking light above it. Fire a grenade at the circuit panel to blow it down and get the Rocket Launcher.
4. Follow the platform to a ladder and climb it. Shoot the enemies above and below. You can drop down for ammo, then push an explosive barrel back over to where you dropped to climb back up, or go back outside and jump down to the platform again.
5. Follow the tunnel in this room outside to a long stair case. Watch out for Icarus as you fight your way down.
6. At the bottom is the exit. Look out for Berserkers and Mutants flanking you as you make your way to the exit.

Upper Mines

1. Inside the Upper Mines, fight your way through the first two rooms, killing the Light Guards in your way.
2. Take the lift upwards, and fight through the linear path all the way to an outside area. There will be lots of Gunners, Icarus, and other enemies, so bring some heavy firepower.
3. The outside area has a deep hole with a fan and an exit near it. Ignore that exit for now and enter the nearby tunnel going down.
4. Follow the linear path to the next vast area. There are quite a few Gunners to blast through, along with Gladiators. Use the Hyperblaster to carve a path. When you reach the area with the flame traps, hug the wall opposite of the trap, and slip past the last pair.
5. In the outside area, ignore the other exit for now and take the stairs down.
6. Battle your way through the hallway into the command center and hit the center button.
7. Upper Mines Secret #1: Shoot the computer panel to the left of the button that is sending out sparks to blow it up and reveal a Quad Damage.
8. Watch out for Icarus and take the other exit. You can step on the button pad here to make a shortcut back to the earlier areas.
9. Upper Mines Secret #2: Stand on the button pad facing the newly-raised bridge, then turn right 90 degrees and shoot the wall ahead to open a secret room.
10. Retrace your steps to the area with the deep pit. Climb down the steps here and take the exit portal.
11. Follow the linear path through the next two rooms, shooting all in your way, into the next area. Watch out for Mutants.

Borehole

1. The mine elevator is in the room to the left of the start. It's not currently operational, and your goal is to restart it. This level has a secret exit that can help you save time completing this mission.
2. Follow the linear path ahead to a room with stairs leading down. Use rockets to flush out Gunners shooting from catwalks above and the Machine Gun for Guards below.
3. At the room with the stairs, blast all the Berserkers, making sure you can see them all before taking them on, then go down and take the doorway out.
4. Borehole Secret #1: Shoot the barrels underneath the stairs and grab the Combat Armor.
5. Follow the linear path along the catwalk, shooting all in your way. There will be a Gladiator and some Guards; if you fall, you'll have to battle a slew of Mutants, Guards and Gunners to a lift that will ride you back to the start of this area. There's a Quad Damage and a secret down there if you are interested.
6. Borehole Secret #2: The path below the main catwalk has a 90 degree corner between two sewage lines with water on the floor. The water is actually deep; dive in and swim down to the Adrenaline. You can get to this area quickly by jumping down the well in the same room Borehole Secret #1 is in.
7. At the end of the path, hit the two buttons. It will turn on the giant drill, and unleash two Gunners. Kill them with the Hyperblaster, then follow the steps for Borehole Secret #3 to exit this level into the Drilling Area.
8. Borehole Secret #3: One of the secret panels the Gunners blasted through has a weird "circle" on the back wall inside it. Shoot the wall and open a secret panel.
9. Collect the goodies for Borehole Secret #3, then climb down the ladder and wait for a track platform to travel upwards. Jump onto it and ride it all the way up to the level exit.

Drilling Area

1. Bounce grenades on the walls to slaughter the Gunners and Gladiators below, then drop down and throw the lever to lower a bridge.
2. Fight your way down to the bottom floor. Move carefully past the crushers, and watch out for Gunners lurking around corners.
3. At the bottom floor, take the exit. You'll be back in the Borehole, underneath the very elevator you needed to activate.
4. Hit the switch to lower it to your level, then hit the rightmost of the pair of switches in the middle of the platform to lower it to the bottom level.
5. Take the exit here into the Drilling Area proper.
6. Use rockets to blow up the Gunners here, then destroy the two power cells to open up the central hole.
7. Drilling Area Secret #1: Drop down the hole and at the first turn left, stop and shoot the flashing crack in the wall. Grab the Invincibility.
8. Follow the path, shooting any Mutants in your way. In the area with the giant laser device, throw the lever to have it blast a hole in a ground. Drop down the hole.

Lower Mines

1. Kill the Technicians and throw the lever. It will start up some track platforms for you to ride.
2. Ride the platforms to a forked tunnel. Do not go down the tunnel with the corpse and items, it's a trap. Instead, go right, blasting through the Technicians and Gunners in your way.
3. The path leads to a Gunner guarding a lever; kill him and throw the lever to squish the Tank standing around below.
4. Drop down and hit the button to drill a hole in the hole in the wall.
5. Enter the hole, then hustle before you are run over by a drilling machine.
6. Kill the Technicians quickly in the next area, as an earthquake will occur, possibly throwing you off the bridge.
7. Keep going and slaughter all in your path on the way to a giant circular lift. Ride it up to an exit leading back into the Drilling Area.
8. Inside this new section of the Drilling Area, if you wish, you can return to the previous section by diving into the water and swimming through the duct. Otherwise, follow the catwalk out.
9. The path leads to the exit elevator, guarded by guards and a Tank. Take them all out; do not blow up the barrels to the right of the entrance or you will miss a secret.
10. Drilling Area Secret #2: You must climb the crates to the right of the exit elevator up to the Adrenaline. You'll need to climb onto an explosive barrel onto the crates, or "rocket jump" by firing a rocket into your feet while jumping to propel you upward.
11. Ride the exit elevator out of the level.

Mission 5

Receiving Center

1. Kill the Guards and hit the button ahead to open the large red hatch.
2. Drop down, kill the sharks and Flyers, then climb out and follow the tunnel into a lava-filled room.
3. Drop down onto the platform below, kill the Guard, and hit the button to make a bridge.
4. Cross the bridge and kill the Gunners with heavy firepower. Throw the lever to drain the lava.
5. Hit the button in the now-drained lava pit to lower a hatch door, then go around and climb onto the lift to jump onto the hatch.
6. Enter the hatch and climb the ladder. You'll fight your first Brain up here; get behind him and shoot. Don't stray too far ahead or a Gladiator will join the battle.
7. Follow the path to a button and hit it, then backtrack to find three moving platforms. Ride them up and drop down into the next area.
8. Receiving Center Secret #1: After dropping down from the three platforms, look at the three nooks ahead and walk into the middle metal plate (it has a completely different texture from the rest of the surroundings). It will open to reveal a stash of goodies.
9. Exit the room and follow the lava bridge to a button on the other side. Press it to unlock all doors in the area and turn off the laser traps.
10. Receiving Center Secret #2: With the laser traps down, you can go outside to the bridge over the culvert. Drop down into the culvert and search for an easy-to-spot niche that leads you out and gives you your first Rail Gun.
11. Receiving Center Secret #3: From Secret #2, go to the other side of the bridge and jump onto the waterfall ahead. You'll have to either jump precisely at the last second or use a rocket jump. Dive into the water to reach a small secret level named "Sudden Death". In Sudden Death, your goal is to collect as many weapons, ammo, and items as you can before the 30 second timer runs out, including a Rail Gun and Quad Damage.
12. Near the hatch you first dropped down is another door, now unlocked. Head in and kill the Gunners and Guards.
13. Go further ahead; a Guard will try to cross a bridge and it will explode. You can still cross by simply using the steel flooring to the right of it. Be aware that the crates here are explosive and there is a Gladiator lurking about.
14. You can drop through the hole in the steel flooring for supplies. Otherwise, skip everything else here and find the exit to the Processing Plant.

Processing Plant

1. Kill the Guards, then go up the spiral stairs and kill the Gunners. Press the button they are guarding.
2. Continue on and kill the Gunners and Tank, then ride the lifts upward as they rise out of the acid. Get off them when they reach the ledge above as soon as possible or you will be killed by cutting devices at the top.
3. Kill the Gunner and press the button he was guarding, then continue.
4. Processing Plant Secret #1: Right near where this Gunner was standing is a red button on the ceiling. It's in the small diamond-shaped nook seperating the two areas. Shoot the red button.
5. Continue on and kill the Guard guarding the processing machine. Press the button in front of him to shut it down and raise a bridge. Watch out for the Gladiator.
6. Processing Plant Secret #2: Go up the small incline from the processing machine button. There is a chute you can drop down here onto a secret ledge below that holds a Quad Damage. Step off the upper ledge going backwards and correct your fall onto the secret ledge.
7. Cross the bridge and enter the next area. Kill the Parasite and drop down. Open the door here and hit the button inside.
8. Kill the enemies attacking from behind and take the only other exit out of this room. Fight your way into the next lava-filled area.
9. Cross to the other side, killing all the sniping enemies, then travel as best you can up the conveyor belt towards the button to press it and stop this machine.
10. Processing Plant #3: With the conveyor belt now shut down, jump onto it and crawl into the chute it trails out from.
11. Use the nearby lift and enter the next room. Kill the enemies, watching out for the Gunners above. Press the button here to shut down this machine.
12. Continue on and fight your way into the next lava-filled room with two staircases. Press the button in front of the grinders to shut them off.
13. Continue on and ride the lift up. At the fork make a right into the room with the tube death trap. Shut down this machine by pressing the button.
14. Go down the other path, using the platform to jump the gap over the acid. In the next room, take out the enemies and shut down the final machine.
15. A door nearby will open, allowing you to shortcut back to the start of this level. Return to the Receiving Center.
16. Back in the Receiving Center, you'll notice to your right two platforms over a laser trap pit. Shutting down all the machines in the Processing Plant sets these platforms in motion, so use them cross the trap pit.
17. Watch out for a few enemies as you follow the linear path all the way to the exit elevator to the Power Station.
18. Receiving Center Secret #4: Right in front of the exit elevator is a button in plain view on one of the red-colored building supports. Shoot it and go around the supports to the secret stash.

Mission 6

Power Station

1. Cross the bridge into the Power Station building, looking out for Berserkers. Don't drop down off the bridge.
2. Power Station Secret #1: Go to the left when you enter the building and shoot the flicking light in the ceiling. A secret cupboard with medkits and Adrenaline will open up right in front of you.
3. Go into the main antechamber and two Iron Maidens will appear. They are easily wasted with rockets.
4. Power Station Secret #2: Shoot the flickering explosive barrels in the room with the Iron Maidens, then enter the secret passage and follow the path to your first BFG10K. There will be a lot of enemies on the way.
5. Face the big relief on the wall and make a u-turn. Go forward around the wall supports to get Body Armor and a lift leading down.
6. Go down the lift and up the ladder ahead. You're now under the bridge and there's a Tank Commander down here. However, from this location you'll be behind a wall with a narrow slit to shoot through, allowing you to very easily waste him. Test out your BFG10K if you want to.
7. After the Tank Commander is dead, grab the Red Key he guards and proceed back to the Iron Maiden room.
8. Take the only other exit out and follow the path. Watch out for explosive crates and backspawning Iron Maidens.
9. Once outside, clear it of enemies and drop down the flame hole when the fire subsides. Kill the Gladiator.
10. Take the lift the Gladiator guards up to the exit into the Reactor.

Reactor

1. Kill the Gunners, then clear the Gladiators out on both sides of the main antechamber.
2. From the entrance, take the left door as you need a Data CD to unlock the other. Kill all in your way. The Rail Gun and Rocket Launcher will be useful here.
3. Fight your way into the big room with the two ramps leading down and take the Data CD. This unleashes two Iron Maidens, a Gladiator, and any other nearby enemy still not yet killed. Use the Hyperblaster or Rail Gun to get rid of them quickly while dodging their shots. The Iron Maidens' ambush point has some Body Armor for you to take.
4. Go back up and open the locked door with the Data CD. Carefully slip past the blue lasers, then follow the path along the catwalks, killing all in your way.
5. Go down the lift at the end and ride it down. Follow the path to the reactor itself and hit the nearby button. It will lower down the forcefields in the exits of the reactor room. Note the other door by the nearby lift; it leads to the Big Gun, but the door is currently locked.
6. From your entrance into the reactor room, take the exit on the right. It leads into the Cooling Facility. Look out for a few Gunners on the way there.

Cooling Facility

1. Grab the supplies and jump into the pipe.
2. Don't exit out the pipe too quickly or you'll be mobbed. Instead, clear out the Gunners and Gladiators with the Grenade Launcher.
3. Drop down and search this open area for a button to press. It will open up a large passage in the floor.
4. Drop down into the passage. You'll land in a sewage line. Kill the Technicians and get the goodies in the nearby dead-end, then follow the sewage current.
5. Cooling Facility Secret #1: As you follow the sewage current after the first turn, look for a ladder on your left. Climb it downward and grab the goodies in the nearby shaft.
6. If you are having trouble moving against the current, try strafing against it. The current will lead you past some Iron Maidens; watch out for them.
7. The current empties into a basin. Use the lifts to climb out. Take out the Berserkers and exit through the door.
8. Cooling Facility Secret #2: When you enter the basin, take the righthand lift upward to the upper ldge. Take a few steps to the right and walk off the ledge going backwards, then press forward as you fall so that you land on a ledge holding a Megahealth.
9. Follow the only exit out, killing Gunners and Iron Maidens, until you enter a room with a massive pump. Press against the valve handle on it.
10. With the pump on, ride the section moving up and down into the area above. Head over to the button on the ledge and press it. The two pistons in front of you will start moving.
11. Cooling Facility Secret #3: After hitting this button, you will hear an explosion. Drop down to the bottom floor of this area and look for a blown-out hole in the wall containing Body Armor and Quad Damage.
12. Climb up the pistons onto the catwalk and follow it out to a reservoir outside, blowing away all in your path.
13. Follow the current of the water main leading out of the reservoir, blasting all in your path, until you encounter a hole in the ground.
14. Drop down into the hole, and follow the shortcut back to the Reactor.
15. Back at the Reactor, return to the reactor core and this time take the other doorway previously blocked by the forcefield.
16. In the next room, take out the two Berserkers, and then continue.
17. Reactor Secret #1: In the room with the Berserkers is a secret panel you can shoot. It's on the center edifice with the map, on the opposite side of the map, facing the door.
18. Enter the next room, kill the Gladiator if he's still there (you may have killed him already), then proceed forward into the door across the hall.
19. The path leads into an outside area with three Iron Maidens. Kill them from inside the entrance portal, then kill the Flyers waiting to ambush.
20. Go down into the tunnel and follow it to a pipe hole. Jump down it to enter the Toxic Waste Dump.

Toxic Waste Dump

1. This area is filled with toxic waste, so be careful not to fall in it unless you are wearing a Environment Suit or Invincibility. From the start, follow the path, blowing away all enemies you find.
2. The path leads to an outside area with a moat of toxic waste. Find the lift and ride it up, then take the exit door.
3. Instead of going up the stairs inside, go right to the dead-end. There's lots of supplies and you can waste all the Gunners and Tanks from your position with the Rail Gun.
4. After at least thinning out the troops on the upper floor, go ahead and storm it from the stairs, then ride the lift up to the exit tunnel. If you wish to get the Ammo Pack on the remote ledge, jump from the upmost ledges from the right onto the piping, then follow the piping to it.
5. Follow the path outside onto the bridge, and waste all the enemies guarding it.
6. Toxic Waste Dump Secret #1: Below the bridge is a channel of sludge. Use an Environment Suit or Invincibility, and drop down onto the channel. Follow the current to the secret, then quickly get out of there.
7. Go across the bridge into the corridor and at the first turn, waste all the enemies at the far end of this corridor with the Rail Gun or other long range weapon. They are guarding an Environment Suit; you can save this later for a secret.
8. From the entrance to this corridor follow it down to your first possible left and take it. Blow up the barrels on the left to blast open access to a button, while wasting the Gladiators and Gunners. Press the button to open up a hatch.
9. Get out a strong weapon and drop down. You'll need to blast your way through a mob of Gunners to get to Pumping Station 1.

Pumping Station 1

1. Go left, sweeping out enemies along the tunnel into the main area. Kill all the enemies.
2. Follow the path then take the lift up. Take out the enemies in the room, then secure the next room ahead before entering it.
3. Pumping Station 1 Secret #1: From the lift you just rode up, follow the tunnel into the next room, observing the piping in the ceiling as it ends into the next room. Shoot the blinking florescent light to the right of where the pipe ends.
4. Pumping Station 1 Secret #2: Across from Pumping Station 1 Secret #1 are large pipes embedded in the wall. One of them has a crack; shoot the crack with an explosive weapon.
5. Pumping Station 1 Secret #3: Dive into the pipe you blew open for Pumping Station 1 Secret #2. Follow the current to a room with another pipe. Jump into this pipe to get emptied into a basin. Shoot the grate right in front of where you emptied to; a message that reads "One more to go..." will appear. Shoot a second grate high above the first one and a secret stash with a Quad Damage will reveal itself. Take the nearby door to get back to the main path.
6. From the room holding Pumping Station 1 Secret #1 and #2, follow the path into the room with the pumps themselves. Hit the button to turn them on, then leave through the exit door into Pumping Station 2.

Pumping Station 2

1. Fight your way through the corridor. There will be a lot of enemies from the front and Gunners sniping from behind on elevated ledges, so look out for them.
2. After the second turn, you will encounter a door on your left, locked and in need of the Blue Key to open. You can shoot the relief next to the door for Body Armor. If you want to gain actual secrets, drop down from here to the floor below. Otherwise, go right.
3. Pumping Station 2 Secret #1: After dropping down, go left and drop down to the platform below. Three Technicians will come out of a culvert of toxic waste. Kill them, then use an Invincibility or Environmental Suit and race down the culvert until you come across the secret.
4. Pumping Station 2 Secret #2: After getting the first secret, follow the main path. When you get to the room with the hordes of Guards and Technicians, look at the metal embankment to the left above the slime river and shoot the loose panel. Climb in for Invincibility.
5. If you are coming from Secret #2, you can continue forward and ride the lift up to the room with the Blue Key. From there, take out the loads of enemies and Tanks inside the pumping room; use the BFG10K or other strong weaponry to wipe them out. If you chose not to jump down from where you got the Body Armor, you'll be coming from the other end.
6. After clearing the pumping room, hit the switch. Get the Blue Key if you haven't, then head to the door that needs the Blue Key.
7. Open the door and fight your way through the linear path to the end of this level. You will need to hop over a pool of toxic waste to reach the stairs leading back to the
8. Pumping Station 2 Secret #3: It's inside the pool of waste you have to leap over. Use an Invincibility/Environment Suit, dive in, and grab the Quad Damage in a niche above the spinning fan.
9. You'll be back at the Toxic Waste Dump. Kill the Tank and his friends with the BFG10K, then continue forward.
10. Fight your way to a nearby button, then press it. Look out for Icarus and Gunners, killing them all before jumping over the blockades.
11. You'll notice the main corridor you traveled through earlier is now loaded with blockades and enemies. Snipe all the Gunners and other enemies with the Rail Gun.
12. Toxic Waste Dump Secret #2: In the main corridor is an Environment Suit you should have saved earlier. It's on the edge of the corridor overlooking the toxic waste below. Collect it and dive right in the waste, swimming down the hole and following the tunnel to a batch of goodies, including Invincibility. You can then surface through the hole near the goodies and quickly climb out near where you fought the Tanks. Technically you can go for this secret at any time, but if you haven't completed Pumping Station 2 yet, the second hole will be sealed off, forcing you to risk racing back to safety the long way.
13. Fight your way down the main corridor until you hit your first left. Go down it, killing all the enemies hiding behind the blockades.
14. At the end of the road is an exit door. Completing Pumping Station 2 unlocks this door (otherwise, you'll get the message "Access Denied" if you attempt to open it), so go ahead and enter.
15. You'll be back at the Reactor. Step on the button pad to raise a bridge, then make your way back to the reactor core. There will be constant earthquakes along the way, and the road back is flooded with toxic waste; make sure to wait out the earthquakes before progressing over dangerous areas.
16. When you enter the reactor core, take the lift there up to the now-opened door to the Big Gun.

Mission 7

Big Gun

1. This is a very brief mission. The first thing you must do is walk into the boss' lair, the Flyer Commander.
2. The Flyer Commander has a few extra Flyers helping him, so waste them first and circle strafe around him while piling on damage with the BFG10K. Four or so direct hits will finish him.
3. With the boss dead, you can now open the door with the orange crest on it. Do so.
4. Blast any Guard in your way as you progress to the back of the compound. Press the button you find there.
5. Quickly return to the Flyer Commander's room. The other locked door in there is now open. Hurry in and run till you find the escape pod, then climb inside before the countdown ends to finish this brief mission.

Mission 8

Outer Hanger

1. You start Mission 8 in the Outer Hanger, but you can access the secret level Comm Satellite right near the start of the Outer Hanger level. To begin, exit the hanger and go outside. Kill the enemies and raise the bridge using the button pad.
2. Drop down into the water below, then quickly surface to kill the Barracuda Sharks.
3. Outer Hanger Secret #1: Enter the nearby door after killing the Sharks. There's loads of Enforcers and Gunners inside. Kill them all, then jump over the curve in the big brown pipe inside, next to the door, for Adrenaline.
4. Outer Hanger Secret #2: In the water with the Barracuda Sharks is a red power cell by the spinning fan. Shoot it and the fan will stop. Surface and dive into the water hole nearby to swim down the pipe into the next area. There are goodies on the island nearby and up on the nearby ladder. Watch out for lots of enemies including Icarus and Tanks.
5. Outer Hanger Secret #3: After securing the area where Secret #2 is, just enter the nearby doorway and hop into the blue aura inside. It will eventually teleport you to the Comm Satellite proper.

Comm Satellite

1. At the Comm Satellite, you'll notice that gravity is substantially lower. You can jump to massive heights and float slowly when dropping down.
2. Close the bay doors by pressing against the nearby console first, then collect the items, then ride the lift up.
3. On the second floor, battle past the massive horde of Flyers and Icarus, following the path past a forcefield. Go into the first electronic door you can find.
4. Comm Satellite Secret #1: After opening the door, look down to your left at the girders below. Drop down to them and follow them to the Adrenaline. If you slip and fall off these girders, you'll be lost in space, so save first.
5. Kill the Technicians in the next room and open the next door to take the lift up.
6. Follow the path through the station, shooting all in your way. At the next door, instead of opening it, go right around the shimmering blue structure and step on the button pad. This opens a computer panel right next to you. Shoot the panel to shut down all the forcefields in this level.
7. Enter the next door and follow the path, shooting all in your way. When you spot another tunnel leading to the left, take it.
8. You'll be in an open arena, taking on another Flyer Commander. Kill him with the BFG10K. Don't fall into outer space; if you fall onto the lower level, use the nearby lift to get back up.
9. Once the Flyer Commander is dead, jump into the button pads on the ceiling on the second floor. There are four total, one at each point of the "circle". This will destroy the communications dish.
10. Exit this room the way you came in and continue on the main path to a door that leads to the exit teleporter.
11. Comm Satellite Secret #2: Stand in front of the door going to the room with the exit teleporter, then turn right. Jump off the ledge here into the darkness forward and to the left. You want to land on a ledge holding Adrenaline. To find it in the dark before you jump, try shooting rockets.
12. Once in the room with the exit teleporter, close the bay doors here and collect the goodies, then use the teleporter.

Research Lab

1. You'll be back at the Outer Hanger, right where you first teleported from. Return to the start of this level via the lift at Outer Hanger Secret #1.
2. Hit the button pad outside if you haven't to raise the bridge, then fight your way inside to the scanner room. Watch out for Medics attacking from behind and make sure to gib corpses.
3. In the scanner room, you'll see a blue forcefield that can't be shut down until you get the head of the Commander. Enter the nearby exit door to go to the Research Lab.
4. This area has hordes of Parasites, Brains and Medics, often attacking in ambushes; try to have the Chaingun or Rail Gun ready for them (the latter is great at long range and the Brains are weak to it). Hit the nearby console button to open the first locked door, then follow the linear path, blasting all in your path till you hit a fork in the road.
5. Take the lefthand door and blast your way along the linear route to a torture chamber. Hit the console buttons to produce a Blue Key; take it.
6. Go back and take the other fork. Blast your way along the path to a lift and ride it down to Floor 2.
7. Hug the left-hand walls and follow them over to an observation center with a console. Hit the console to raise a security bridge.
8. Go along the main route, ignoring the orange door for now. You should soon come across the security bridge. Use it to jump to the two buttons hidden in the nooks to your left; this should lower all forcefields in the Research Lab.
9. Research Lab Secret #1: To the right of the security bridge is three prisoners held in barred cages. One of the prisoners is dead, and the bars of his cell cracked. Shoot the bars with an explosive weapon; it will blow up and reveal a nook with Quad Damage.
10. Go back to the orange door you ignored earlier. Enter it and ride it up.
11. Get out of the lift and grab the Commander's Head by the surgury machine. Return back to Floor 2.
12. Go back to the security bridge and cross it. Follow the path to another lift. Ride it back to Floor 1.
13. Exit the level via the way you came in. Watch out for Iron Maidens.
14. Back at the Outer Hanger, go to the scanner room and press the odd-looking button inside to lower the blue forcefield.
15. Follow the opened path to the Inner Hanger.

Inner Hanger

1. The beginning room will have a lot of enemies lurking around in it, including Brains and Berserkers, and some of them spawning from secret ambush points. Tread carefully.
2. Inner Hanger Secret #1: Right off the bat you should see a supercomputer setting off sparks. Shoot it for the secret.
3. After clearing out all enemies, open the bottom hatch door.
4. Jump on the turbine to get shunted up into the area above. Kill the enemies and use the console to shut the turbine off.
5. Open the nearby hatch door to go back into the beginning of this level. Return to the turbine and drop down to the floor it is on.
6. Follow the path into a dead-end with two Gunners. Kill them and hit the button to open up holes in the floor.
7. Drop down the holes into the area with the turning cross-wheel. Make your way out into a water-filled pool, then kill the enemies in there.
8. Inner Hanger Secret #2: There are a stack of brown crates in one of the corners of this room. Shoot them with an explosive device to get a Quad Damage.
9. The staircase nearby will return you to the beginning of this level. Instead, take the only other exit and fight onward.
10. Up next is another pool, this time with sliding blocks. You don't need to ride them for now, just follow the blocks to a ladder with a button and press it.
11. The button turns on another sliding block. Ride it to another button and press that. It will lower three platforms leading to a lift in the center of the room. Ride that lift up.
12. Inner Hanger Secret #3: Hitting the second button here opens a hole in the floor right in front of it, beneath the water. Swim down and hug the walls going left for an access hole leading to the secret.
13. The lift leads to the top of two giant gears. Drop down into the water. The watery tunnel doubles back to the sliding block room, while the stairs leads to another Flyer Commander.
14. Follow the linear path, blasting all in your path, until you reach a long shaft. This shaft has the Flyer Commander; down him with the BFG10K and hit the button pad to raise a bridge.
15. Inner Hanger Secret #4: After killing the Flyer Commander, dive into the water and swim in front of the island; you should spot the secret.
16. Go into the only exit and kill the Gunners that are lurking. Hit the button to raise a ladder and climb out.
17. Cross the newly-raised bridge and enter the next area. Battle your way through the troops to a lift, then to a room with a lever. Throw the lever.
18. Take the only other exit out and blast your way to the exit elevator.
19. Inner Hanger Secret #5: Before getting on the exit elevator, look for three nearby brown crates, similar to the ones for Inner Hanger Secret #2. Right near them is a loose panel on the wall you can shoot to reveal Body Armor.

Launch Command

1. Launch Command Secret #1: Right off the bat you should see the tall platform underneath the spinning device floating in the air. Jump onto the platform with a "rocket jump" (shoot a rocket into your feet while jumping to get thrown into the air), then wait until you get the message "Secret Area! You crazy rocket jumpers!" . A slew of goodies will then magically appear around the platform, including a BFG10K.
2. Get ready to fight hordes of Tanks, Gunners, Iron Maidens, and other enemies. The Grenade Launcher, Rocket Launcher, and Rail Gun will be very helpful. Battle your way into the intersection and go right.
3. Kill all the enemies on your floor, then the ones above. Right an elevator up and turn the valve.
4. Go into the exit on the other side. Enter the door on your left.
5. Kill all the enemies, then use the elevators to reach the two valves, then jump to the ledge with the third valve.
6. Return to the previous room and take the only other brown-colored door. The room is identical to the first valve room. Kill all the enemies and turn the handle.
7. Go back to the previous room and take the door marked "Launch Systems". Kill the guards and shoot the computer panels. One of them has a Power Shield hidden behind it.
8. Go to the room with the three valve handles and take the now-open hallway to the exit door; the forcefield for it lowered when you shot the computer panels.
9. Launch Command Secret #2: Before leaving this level through the hallway, shoot the cracked glass on your left and swim into the water for the secret stash.

Outlands

1. Go outside and get ready to fight loads of Guards and Enforcers throughout this level. There will be a small army outside the bridge.
2. There's also a turret gunner here. To take him race around behind hin and shoot him down before he can turn around.
3. You can take the tunnel down and fight through the armies of guards, or drop into the water and fight off sharks as you swim to the end. Either way, be careful.
4. Past all the enemies is a corpse holding the airstrike marker. Take it and continue.
5. The path ends into two bunkers connected by red pipelines. Follow the pipelines till you find a gap in one. Touch it to automatically set the marker.
6. Once the marker is set, run like crazy to the bunker on the opposite side and fight your way in to avoid the incoming airstrike.
7. After the airstrike passes, enter the bombed bunker and hit the exit button to end the level.

Mission 9

Outer Courts

1. Go outside and get ready to fight a small army of enemies. There will be tons of Icarus, Guards, and Gladiators around the cliffs and in the caves below, so tread carefully as you explore.
2. After clearing the area, climb onto the cliffside to the left of the entrance and follow it to the building roof on the other side. Step on the button pad, then drop down.
3. Outer Courts Secret #1: From the button pad, follow the cliffside to the left as it wraps back around to the roof of the entrance you came in from. There's a button there; press it to get the message "A secret passage opened somewhere". That secret passage is back at the very start of this level; enter it for Body Armor and other goodies.
4. Go into the main structure ahead. Watch the bridge going inside as it's actually a trap door; hug the sides to cross safely.
5. Outer Courts Secret #2: Before going into the building, go into the nearby caves and look for a dead-end with some lava. You should see a crack in the wall with some items floating behind them. Blow the crack up with explosive weaponry and get the goodies.
6. In the next area, collect the ammo and head into the palace ahead. Take out the Super Tanks (they can take more hits than the regular Tanks), and enter the palace.
7. An alarm will sound and you'll be under fire from behind from Guards and Icarus. Kill them all, then continue.
8. Outer Courts Secret #3: Before going into the palace, go back to the outside area from before (watch the trap door). You may have heard Medics earlier over there; they are now on the loose along with some Icarus. Kill them all and go to the button you pressed for Secret #1. There's now a new passage right near it, where all the enemies were lurking in. Go inside and get the secrets.
9. In the palace, take out the Super Tanks with the Rail Gun or Grenade Launcher. Go leftward after you killed them all to enter the sewer.
10. Kill the Icarus, then drop into the sewage below. Follow the current until you hit an obstruction, getting the message "This path is blocked by debris". Shoot it with an explosive weapon.
11. Continue on into a reservoir, and use the Rail Gun to clear out all the enemies as you make your way up to the top floor of this area.
12. On the top floor is a room holding the Data Spinner. Shoot the glass and collect it.
13. Outer Courts Secret #4: Right next to the Data Spinner is a button pad. Step on it, then turn around and you'll see the secret right behind you.
14. Hit the button where Secret #4 is to raise a bridge, then cross it to enter a tunnel.
15. Continue on into a shaft that will drop you down into the same river of sewage you swam through earlier. Back track to the area where you first dropped into the sewage, using a lift to climb out.
16. Go back through the palace to where you fought all those Super Tanks and find the ornate door leading to the Lower Palace.

Lower Palace

1. Get ready for a huge firefight with Guards and Berserkers at the start. Kill them all, then go left from the Quad Damage.
2. Lower Palace Secret #1: To get the Quad Damage, shoot the mural with the demonic figure behind it, then turn around and shoot the counterpart mural up high above the entrance doorway.
3. Follow the linear path, killing all in your way, until you hit a forcefield with some Guards hiding behind it.
4. Crawl through the hole in the nearby grating to land on the water below. Note the ladder, you'll use it later.
5. Lower Palace Secret #2: Look around in this water pit for a crawl space and follow it. The Adrenaline is the secret; continue past it and shoot the grate to continue on your journey.
6. In this new area past the grate and Secret #2 is a horde of guards and Berserkers. Kill them and continue. Ignore the red door below for now, it leads back to the Outer Courts. Take the only other exit out.
7. Follow the linear path. There will be tons of baddies, including Brains, Guards, and Technicians coming out of the red square in the floor. Note the yellow door, and ignore the corridor with the blue lasers for now.
8. The path ends into the other side of the forcefield you saw earlier. Open the nearby door and hit the console button to shut down all the red forcefields for this level.
9. Outer Courts Secret #5: Return to the room where you got Secret #2. Open the red door and go back into the Outer Courts. Kill all in your path and at the dead-end, some Guards will blow up a hole in the floor for you. Dive into the hole to find yourself back in the sewage line. Swim to the right and follow the path. When you see the corpse sitting on the floor, swim forward a little bit, then surface and turn around. There should be a ledge with a Rebreather and a medkit. The secret stash is here; it was sealed off previously due to the red forcefields.
10. Go back to the water pit where Secret #2 was and this time, climb the ladder. A secret panel will open.
11. Follow the path through the this secret tunnel back to near where the Quad Damage at the start of this level was. You can climb the lone ladder on the way for Invicibility. Note the yellow forcefield nearby the ladder as well; this is a secret you can get later.
12. Go past the Quad Damage pedestal to the other route you haven't taken. Since the red forcefields are down, it's now open. Kill the Tank and enter the atrium ahead.
13. Kill any enemies that attack you, including some from the balcony. When finished, choose the left hand route first.
14. Kill all in your way; you'll eventually hit a blaster cannon trap, which fills the hallway with blaster fire. One option you have is to shoot the trick button above the cannons; doing so raises a metal plate, allowing you to slip past them.
15. Lower Palace Secret #3: It's possible to permanently shut off the blaster cannons by shooting a secret plate. Just stand around the corner from the far end of the blaster cannons, and simply shoot the wall right in front of you. You will get a message saying the blaster cannons are deactivated. This actually counts as a secret bonus.
16. Past the blaster cannons are mobs of enemies, including Super Tanks. Kill them all, then take the nearby elevator to the Upper Palace.
17. Lower Palace Secret #4: Before getting on the elevator, shoot the LCD panel with the yellow and red text right near it. Enter the secret passage and get the goodies.

Upper Palace

1. You can hit the console button to lower the forcefield gates here. Do so for the left-hand one, taking the lift inside upward.
2. Upper Palace Secret #1: Before taking the lift, lower the right-hand forcefield and shoot the ceiling just past it. It will open a secret cubbyhole filled with goodies.
3. Past the lift, kill the enemies and at the fork, go right.
4. There are two doors here; go into the left-hand one and kill the Gunners. Take the Data CD.
5. Upper Palace Secret #2: Return to the fork and take the other door into an area with a bridge and another demonic mural with explosions coming out of it. Kill the Super Tank in your way if he's not yet dead. Cross this bridge and jump down the small hole right next to the blue forcefield. You'll land in a secret room with goodies.
6. Upper Palace Secret #3: After landing in the room where Secret #2 is, save your game, then drop down the exit hole. You'll land in another blaster cannon booby trapped corridor. Dive off of the ledge here into the lava and you should land on a safe ledge below. Follow the lava back to a small area with Quad Damage and a lift back up.
7. From Secret #3, past the blaster cannons, is the area underneath where you got the Data CD. There's a locked door here you need to open with a Security Pass. For now, get past the blaster cannon trap by shooting the trick button, then continue on and kill all the enemies in the antechamber you run through.
8. Fight your way back to the entrance to this level and return to Lower Palace, and battle your way back to the fork in the atrium. This time, take the door on the other end of the atrium.
9. Fight your way down to the bottom area. There will be loads of baddies, including Brains everywhere. At the bottom is a supercomputer.
10. Touch the two LCD panels on either end of the supercomputer to use the Data Spinner and Data CD. Afterward, touch the central keyboard and collect the new Data Spinner that appears.
11. Go into the exit on the other side of the room, and blast your way through this small area until you find a console guarded by some Brains. Hit the console to open all yellow doors, then continue on to enter the lower sections of the Upper Palace.
12. Lower Palace Section #5: Before leaving to the lower section of the Upper Palace, press against the wall to the left of the yellow door console button. It's actually a secret lever; go back outside and down the hall you came to grab a secret cache of goodies.
13. This new area of the Upper Palace has a lot of backspawning enemies, so watch out. Blast your way through the Guards and Iron Maidens up the stairs.
14. Follow the path and collect the goodies left and right, then head over to the lift, ignoring the elevator below the railing.
15. When you get on the left, ride it to the top and enter the nearby vent. Climb down the ladder here.
16. Upper Palace Secret #4: Before going down the ladder, shoot the nearby secret button in the wall for a stash containing Invincibility and a Power Shield.
17. At the bottom of the ladder, clear this floor of enemies and supplies, then go down the second ladder.
18. On the ledge below, follow the ceiling with the yellow piping here to a computer. Get the Security Pass by jumping onto the computer and crawling into its hole.
19. Retrace your steps back through the Lower Palace, all the way back to the door locked with the Security Pass inside the upper section of the Upper Palace. Open it; inside is the control button for the yellow forcefields. Hit it now to deactivate all yellow forcefields.
20. Return back to the section of the Upper Palace where you collected the original Data CD. Now that the yellow forcefields are down, however, you can collect a slew of secrets.
21. Lower Palace Secret #6: Go into the opened yellow door at the supercomputer room, then follow the path right all the way back to the water pit where Secret #2 was. Climb the ladder to open the secret panel, then climb the ladder you find inside. At the top, jump over to the ammo cache in the storage room, now accessible with the yellow forcefields down.
22. Upper Palace Secret #5: Go back to the section of the Upper Palace with the lift that leads to the Security Pass, and jump down over the railing below near the lift. Two Technicians will bust through the ceiling if you attempt to pass through the now-open forcefield. Kill them and shoot in the hole they came out of for an Environment Suit.
23. Upper Palace Secret #6: From Secret #5, battle through the corridor and hit the button to lower a staircase. Shoot the wall at the bottom of the staircase, near the toxic waste pool, for Body Armor.
24. Upper Palace Secret #7: Use your Environment Suit and jump in the toxic waste pool next to Secret #6. Kick the stone button jutting out above the pool; it will open up the floor beneath you, allowing you to swim in the toxic waste. Follow it to its end, surfacing into an area with another Environment Suit and some id Software easter eggs (including the head of John Carmack should you hit the console keypad here).
25. Stand right where you collected the Data CD, and a small chute will open in front of you. Go in and shut down the communications laser using the console keypad. This will turn off all blue forcefields.
26. Exit this room and enter the nearby door. Fight your way through the hallway to a spaceship. Use the nearby console keypad to open it, then climb in and hit the exit button.

Inner Chamber

1. Follow the path through the Inner Chamber, until you encounter a room with two Iron Maidens on an island over lava.
2. Kill the Iron Maidens, then use the two pistons to hit the buttons they extend to. This opens access to the giant piston in the center; ride it up.
3. You'll see the final boss, Makron, ahead. Ignore it as it's actually an illusion. Instead, step on the button pads, avoiding the red lasers.
4. A horde of Flyers will appear. Kill them and hit the two buttons they were guarding. You may now step on the platform where the fake Makron was standing to head to the final battle.

Final Showdown

1. Collect all the goodies you want, then ride the lifts up. Note the escape pods; you'll need one later.
2. Time to kill Makron. Turn on Invincibility and blow him away with the BFG10K. If you have a full supply of ammo, he will go down, revealing his final form.
3. In his final form, Makron is smaller but still no less a threat. He's armed with every weapon in the game, including a BFG10K, so stay far away from him and shell him with rockets, rail gun shots, and everything else you have till he's dead.
4. Once he's dead, ride a lift back down to the escape pods and find an open one. Enter it and hit the button inside to win the game.
5. id Hall of Credits: This super secret can be accessed after killing Makron. There are two button pads in Makron's arena; stepping on one opens a secret panel near the other. After Makron is dead, drop down either secret panel and look around in the area below for a dead-end with an orange crack in the wall. Shoot it with an explosive weapon to blow open a path to the id Hall of Credits. Enjoy the easter eggs, including the scandalous scene you'll find when you climb down the ladder at the back end of the hall.