Cheat mode
Press "24328" at the main menu to display the cheat menu, with level selection, God mode, and unlimited ammunition options. The sound of a click will confirm correct code entry.
All weapons
Press "48662" at the main menu. The sound of a click will confirm correct code entry.
Unlimited clips
Press "48627" at the main menu. The sound of a click will confirm correct code entry.
Unlimited Ghost Vision
Press "46266" at the main menu. The sound of a click will confirm correct code entry.
All single player levels
Press "67687" at the main menu. The sound of a click will confirm correct code entry.