• A: Jump/Swim
• B: Fire Starbits
• Z: Crouch/Ground Pound/Dive
• C: Reset Camera Position
• Control Stick: Move
• Control Pad: Change camera view
• +: Pause Menu
• Shake Remote: Spin/Activate

Like it's predecessor, Super Mario Galaxy 2 is a 3D platformer that has Mario hopping from planet to planet and galaxy to galaxy in an effort to collect the 242 stars that exist throughout the 7 worlds and 49 levels of the game. Stars are collected by completing level specific challenges that vary from having Mario simply go from point A to point B, collecting a certain number of coins, beating a boss, or win a race just to name a few examples.

Players progress through the game via a world map similar to the ones found in the 2D Mario games like Super Mario Brothers 3, Super Mario World, and most recently, New Super Mario Brothers Wii. By collecting stars, players are able to unlock star barriers and move on to new levels. To reach the final boss and beat the game, players need only to collect 70 stars in order to unlock the final star barrier. However, once players beat the game, the 7'th and final world is unlocked, and in order to access all of those levels, 110 stars must be collected.

Those looking to go even further than that can collect all 120 regular gold stars to cause 120 Green Stars to appear throughout each of the levels. Those who manage to collect all of the green stars will unlock the final and hardest level of the game and will be able to earn the final 2 stars, bringing their total to 242.