Be Invincible:
Go to the Enter Cheat screen and enter EMERPUS for a code. Then turn on that cheat at the menu to activate it.
Get Every Weapon (Weapons must be available in current level):
Go to the Enter Cheat screen and enter TEXAS for a code
Unlimited Ammo:
Go to the Enter Cheat screen and enter MADMAN for a code
Pick level:
Go to the Enter Cheat screen and enter SELLOUT for a code. Now you need to load a saved game to pick the level
Be invisible:
Go to the Enter Cheat screen and enter SLLEWGH for a code.Acquire Everything:Navigate to the Cheats menu at the title screen and input the code “FMNFB”.