Level select
During play pause game and then hold L2 and press up,circle,right,up,left,right,down. Then press select.

Secret Bonus
When you are in the control room you can find three (3) rectangular shaped objects that form one (1) rectangular object. At the top of each rectangle is what looks like a green tape recorder. There are three (3) of these. Get on the side of each one and whack it with your tail. After hitting all three (3) a secret panel opens up and you have yet another bonus round you can play.

3D Cam
Pause game highlight exit and HOLD L2 And type in up,down,up,down,select,select.

Best Ending
Password: R1, R2, X, L2, Square, X, Square, R2, R2, R2, X, L2, Square, X, R2, Square, L2, R2, X, L2, Square, X, R2, Square, L2, R2, X, Square.

98% Complete
Password: Square, Circle, R1, Triangle, L1, R1, L1, R1, Circle, Circle, R1, Triangle, L1, R1, Circle, L1, Triangle, Circle, R1, Triangle, L1, R1, Circle, L1, Triangle, Circle, R1, L1.

Vault Codes
When you have access to the vault, use the following codes:

Debug mode:
Square, Square, Diamond, Circle, X, X (press Select for Debug menu)

Level select:
Square, Circle, Circle, Triangle, X, X

One-liners:
Square, Triangle, X Star, Square, X (press Select for one-liners)

10 Lives:
Square, X, Circle, Circle, triangle, Square

1 Life:
Triangle, Circle, Star, Square, Square, X

Invincibility:
Square, Star, Triangle, Square, Triangle, Diamond

Play as Alfred:
Square, X, Triangle, Square, Star, Star

Play as Cuz:
Square, Diamond, Square, Square, Triangle, Diamond

Play as Rex:
Square, Star, Star, Square, Triangle, Triangle

GEX Video 1:
Circle, Triangle, Square, Star, Diamond, Star

GEX Video 2:
Diamond, Star, Square, X, Triangle, Circle

GEX Video 3:
X, Diamond, Star, Triangle, Triangle, Circle

All GEX Videos:
Star, X, X, Circle, Square, Triangle

Eight Hit Paws:
Square, Diamond, Triangle, Triangle, Star, Diamond

Cheat Modes
To enable cheat modes, pause the game, hold the L2 button and press the following:

Debug mode:
Up, Circle, Right, Up, Left, Right, Down. (press Select for Debug menu)

Invulnerability:
Down, Up, Left, Left, Triangle, Right, Down

Select one-liners:
Down, Right, left, Circle, Up, Right (press Select for one-liners)