Ultimate password
Enter "1GOTP1NK8C1DBOOTSON" as a password. This gives you all weapons, unlimited firepower, invincibility and access to all levels.

Level select
Enter "G0LVL" as a password, followed by the level you want to start on. (i.e., "G0LVL14" for level 14.) If you entered the code correctly, the words "Cheat Enabled" will appear.

Power shotgun
Pause the game and press Triangle, Circle(2), Square.

View ending
Enter "FLYTO35" as a password.