Unlock Everything
To unlock everything, go to the Cheats menu at the title screen and enter the code "FMNFB".

Invincibility
To turn on Invincibility, go to the Cheats menu at the title screen and enter the code "emerpus". Then turn on the Cheat at that menu to activate it.

Invisibility
To turn on Invisibility, go to the Cheats menu at the title screen and enter the code "sllewgh". Then turn on the Cheat at that menu to activate it.

Unlimited Ammo
To get unlimited ammo, go to the Cheats menu at the title screen and enter the code "madman". Then turn on the Cheat at that menu to activate it.

Unlock All Levels
To unlock all levels, go to the Cheats menu at the title screen and enter the code "sellout". Then turn on the Cheat at that menu to activate it.

Unlock All Weapons
To unlock all weapons, go to the Cheats menu at the title screen and enter the code "texas". Then turn on the Cheat at that menu to activate it.