Start a game
Complete first level
Do not receive damage when passing level 2
Complete 9 levels
Pass the whole game
Press the mute button 400 times
Play the game for five hours straight
Kill 256 enemies with your shield
Pass the 9th level without taking any damage
Use 50 aid kits
Die 50 times
Ram 50 copters
Kill 4 enemies simultaneously
Run a new version of the game
Get 45 or more HP
Destroy 3 Walls