This is the opening stage to Fieldrunner. As such this is the easiest and most straight forward map in the game. There is only one entrance and one exit, thus making the enemies movements predictable. Play this level until you can complete it without taking any damage and then continue onto the more challenging levels. 

This is the opening stage of Fieldrunners. In it you must hold off 100 rounds of enemies using 4 towers. The four types of towers are a standard machine gun, an ooze gun, a missile launcher and a lightning tower. In addition to the weapons you have to choose from you must lay out a maze for your opponent to traverse. You want to make your opponent take the longest amount of time to get from the entrance to the exit. This will give you the greatest amount of time to damage your opponent.

Starting at round 10 helicopters will start advancing through your field. Aerial units travel above your maze. As such you need to create a large kill zone along the center-line of your labyrinth. This will let you damage ground units as they pass and air units as they fly over. Mostly your maze will consist of primarily machine guns as the walls of the maze as they are the cheapest units but beyond the opening levels they are mostly useless.

Ooze guns should be deployed throughout and always next to a lightning tower, this will help you maximize the damage and efficiency of a lightning tower. Lightning towers will be your major damage dealers but they are also very expensive, therefore you will not be able to deploy too many of them. It is also more efficient to deploy one lightning tower and level it up than it is to deploy three towers separately. Build the center of each line so that it consists of at least one lightning tower, one ooze gun, and at least one missile launcher on each end of that set up, that is four units in total.

As the rounds continue the enemies come in larger waves and with much greater health and defense. At round 40 start considering upgrading your units, start with the ooze guns as they are very inexpensive but allow your units far greater amounts of damage. At this point time you should have roughly five rows for your opponents to travel through. Ultimately you should not need more than eight rows by the end of the level.