Hand Grenade:
Triangle, Circle, Square, Square, L1, and Right.

Mortar:
Right, L1, Triangle, Square, Right, Circle, Left, and Left.

Dummy Decoy:
X, L1, Right, Circle, X, Up, Square.

Super Chain Gun:
Left, L1, Down, Square, Triangle, Up, and Down.

Homing Grenade:
Right, Up, X, Square, L1, L1, and Right.

Bones Airstrike:
Down, Up, Circle, Down, Up, Down, and L1.

Invincibility:
Circle, Triangle, Triangle, Circle, Right, Up, Left, L1, Square.

Bones seal:
Triangle, Right, Circle, Left, Left

Earthworm Jim cow power-up:
Up, Down, Down, L1, Right.

Sniper grenade:
Up, Square, L1, Left, Circle, Triangle.

Homing sniper grenade:
Left, Up, X, Square, L1, R1, Right.

World's smallest nuke:
Down, Up, Square, Triangle, Down, Circle, Circle, Right.

World's most interesting bomb:
Down, Right, Circle, Circle, Left, Left, Up, Square, Triangle.

Thumper weapon:
Down, Up, Left, Left, Triangle, Up, Right, Down.

Twister weapon:
Down, L1, Square, Triangle, Right, Up, X.

Homing bullets:
Square, L1, L1, Right.

Nodie:
Circle, Triangle, Triangle, Circle, Right, Up, Left, L1, Square.

150 hit points and extras:
Square, Triangle, L1, L1, Left, Square, Triangle, Circle, Right, L1.

Full hit points:
Right, L1, Square, Triangle, L1, Down.

Faster speed:
Right, Circle, Triangle, Circle, X. Press R2 during game play to activate faster speed.

Display coordinates:
Down, Down, Triangle, Triangle, L1, X, Triangle.

No opponents:
Up, Square, L1, Left, L1, Square, Square

Strange mode:
Left, Circle, X.

Level Select:
Go to the Title Screen. Press Left, Circle, Triangle, Up, and Square. The Level Select option will appear on the screen.

Free flying:
Do the Earthworm Jim cheat then on the last level jump off the edge of the teleporter and do the e.w.j cheat in the air and you will be able to fly any were you like.