Level select:
Hold L1+ L2 + R1 + R2 at the main menu, press Triangle, Up, Triangle, Circle, Right, then immediately release L1, L2, R1, and R2 when the level select text appears.

Invincibility:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Circle, Triangle(2), Circle, Right, Up, Left, L1, Square.

Extra airstrike:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Down, Up, Circle, Down, Up, Down, L1.

Bones air strike:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Triangle, Right, Circle, Left(2), Circle, Triangle(2), L1, Right. Note: This code may only be enabled during the last level of the game.

Seal:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Circle, Triangle(2), L1, Right. Note: This code may only be enabled during the last level of the game.

Bones seal:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Triangle, Right, Circle, Left(2).

Earthworm Jim cow power-up:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Up, Down(2), L1, Right.

Strange mode:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Left, Circle, X.

Dummy decoy:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press X, L1, Right, Circle, X, Up, Square.

Super chain gun:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Left, L1, Down, Square, Triangle, Up, Down.

Grenade:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Triangle, Circle, Square, L1, Right.

Sniper grenade:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Up, Square, L1, Left, Circle, Triangle.

Homing sniper grenade:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Left, Up, X, Square, L1, R1, Right.

Display coordinates:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Down(2), Triangle(2), L1, X, Triangle.

Mortar:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Left, L1, Triangle, Square, Right, Circle, Left(2).

World's smallest nuke:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Down, Up, Square, Triangle, Down, Circle(2), Right.

World's most interesting bomb:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Down, Right, Circle(2), Left(2), Up, Square, Triangle.

Faster speed:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Right, Circle, Triangle, Circle, X. Press R2 during game play to activate faster speed.

Thumper weapon:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Down, Up, Left(2), Triangle, Up, Right, Down.

Twister weapon:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Down, L1, Square, Triangle, Right, Up, X.

No opponents:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Up, Square, L1, Left, L1, Square(2).

Super gun:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Right, Up, Down, L1, Down, Circle, Left(2).

Homing bullets:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Square, L1(2), Right.

150 hit points and extras:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Square, Triangle, L1(2), Left, Square, Triangle, Circle, Right, L1.

Full hit points:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Right, L1, Square, Triangle, L1, Down.

Nodie:
Pause game play. Press L1, Up, Square. Resume game play and immediately pause the game again. Press Circle, Triangle(2), Circle, Right, Up, Left, L1, Square.