Unlockable: Minigames, Levels and Hats
Set the player 1 name to ROYGBIV.
Cheat: Hidden Hats
In the Options Menu, where you can rename your alien, use the following names to unlock hidden hats for the 2 player game:
cletus
april
superfly
goodman
grrl
abe
princess
dandy
Unlockable: Super Soviet Missile Master mini-game
Finish level 1-5 and the Super Soviet Missile Master mini-game will be unlocked after the intermission sequence.
Unlockable: Hair
Pirate Hat: On level 1-1 destroy Hairy Nanny Daycare
Curly Hair Wig: Destroy the “Fish are like plants” building in level 1-5