Chicken Mode
Unlock chicken mode, then while playing a game, press Back, X(2), Y, A, B. If you entered the code correctly, a message will appear.

Helium Mode
Unlock helium mode, then while playing a game, press Back, X, A, Y, B, X. If you entered the code correctly, a message will appear.

Paper Mode
Unlock paper mode, then while playing a game, press Back, B, A, X, Y, A. If you entered the code correctly, a message will appear.

Huge Head
Unlock huge head, then while playing a game, press Back, A, X, B, Y, A. If you entered the code correctly, a message will appear.

Slow-motion Mode
Unlock slow-motion mode, then while playing a game, press Back, Y(2), B, X, A. If you entered the code correctly, a message will appear.

Chicken head mode
During the game, hold back then hit X, X, Y, A, B.

Enable cheat mode
Finish every objective in single player.

Invincibility
Hold back then press X, X, A, B, A.

Team God-mode
Warning: You cannot finish the game with this cheat turned on. Hold back, then hit B, A, Y, Y, B, A, X, X, X.

Wheelchair characters
During the game hold back then press A, A, A, X, B, Y to have characters in wheelchairs!

Fat Players
Hold BACK and press B, B, Y, X, X, A.

Funny Saying
On the second mission when you go to cross the stream get in the middle of it and try to go into the prone position while you cannot do this he will say "I'm not going swimming".