God Mode
While playing, pause the game and press Down, L1, Up, Square, Start, Start, Circle, Triangle, Triangle, Circle, Right, Up, Left, L1, Square. Unpause the game to enable the code.
Various Cheats
Before you can enter the following cheats, you must first pause the game and press Down, R1, Up, Square:
Bones Airstrike: Press Down, Up, Circle, Down, Up, Down, R1.
Cow Drop: Press Up, Down, Down, R1, Right.
Dummy Decoy: Press x, R1, Right, Circle, x, Up, Square.
Invincibility: Press Circle, Triangle, Triangle, Circle, Right, Up, Left, R1, Square.
Mortar: Press Left, R1, Triangle, Square, Right, Circle, Left, left.
Nuke: Press Down, Up, Square, Triangle, Down, Circle, Circle, Right.
Sniper Grenade: Press Up, Square, R1, Left, Circle, Triangle, Square.
Super Chain Gun: Press Left, R1, Down, Square, Triangle, Up, Down.
Super Speed: Press Right, Circle, Triangle, Circle, x. (During gameplay hold down the R2 button for Super Speed.)
Thumper: Press Down, Up, Left, Left, Triangle, Up, Right, Down.
Tornado: Press Down, R1, Square, Triangle, Right, Up, x.
The Worlds Most Interesting Bomb: Press Down, Right, Circle, Circle, Left, Left, Up, Square, Triangle.