Enter all key taps while the game is paused.

• Level select: UP, DOWN, LEFT, RIGHT, LEFT, LEFT, RIGHT, RIGHT.
• All weapons: UP, DOWN, LEFT, RIGHT, LEFT, RIGHT, LEFT, LEFT
• Infinite ammo: UP, DOWN, LEFT, RIGHT, UP, LEFT, DOWN, RIGHT
• Infinite Necroplasm: UP, DOWN, LEFT, RIGHT, DOWN, LEFT, UP, RIGHT
• No blood: UP, DOWN, LEFT, RIGHT, UP, UP, UP, UP
• Unlock comics: UP, DOWN, LEFT, RIGHT, RIGHT, LEFT, LEFT, UP.
• Encyclopedia: UP, DOWN, LEFT, RIGHT, LEFT, RIGHT, UP, DOWN

While playing the game pause it and enter: UP, DOWN, LEFT, RIGHT, RIGHT, LEFT, DOWN, UP