Cheats
During gameplay, press Start. Press C-UP, C-DOWN, C-LEFT, C-RIGHT. Cheat should appear at the bottom of the menu. At the Cheat Menu, enter in the following codes quickly.

C-LEFT, C-RIGHT, C-DOWN God Mode
(invincibility) C-LEFT, C-LEFT, C-RIGHT, C-RIGHT, C-DOWN, C-UP Visit
(level select) C-DOWN, C-UP, C-LEFT, C-LEFT Butcher
(kills all enemies currently on-screen) C-LEFT, C-UP, C-DOWN, C-DOWN Health
(gives you full health) The following codes can be inputed anywhere, but you must go to the Collect Menu in the Cheat Menu to use them.

C-DOWN, C-UP, C-LEFT, C-RIGHT All Keys C-UP, C-RIGHT, C-DOWN, C-UPAll Artifacts C-RIGHT, C-UP, C-DOWN, C-DOWNAll Weapons Press C-UP twenty timesNo Clipping Press C-UP, C-LEFT three times, C-RIGHT, C-DOWN twiceAll Puzzle Items