Level select:
Pause the game, hold L1 and then press Triangle, Up, X, Down. You should hear a gunshot.
Then Exit to return to the main menu with this new option.
All Weapons:
Pause the game, hold L1 and then press Square, Circle, Up, Down, X, Square. You should hear
a gunshot. Return to the game and you will have all weapons.
Infinite lives:
Pause the game, hold L1 and press Triangle, Circle, X, Square. You should hear a gunshot to
confirm proper entry.
Invincibility:
Pause the game, hold L1 and press Up, Down, Left, Left, Triangle, Up, Right, Down.
Debug Info Cheat:
Pause the game, hold L1 and press Down, Down, Triangle to enable the debug.