Project Overkill PlayStation 1 Cheats

Maximum Health
Highlight Review mission, hold Square, and press Circle, X, Triangle. Release Square, hold Circle, and press Square, X, Triangle. The word "Cheater" should appear at the top of your screen.

Secret Level
In the Throg Breeding Facility you'll find a secret entrance to the "Lost City". Look for it in the lower right-hand corner of the map. You'll need to break through three or four secret doors to find this exit, but it's well worth it.

Refill Ammo
Start a mission as normal. When you transport in, pause the game to bring up the sub-menu. Highlight Review Mission, hold Circle, press Square, release; hold Triangle, press X, release; hold Circle, press X, release; hold X, press Square, release. The word "Cheater" should appear to confirm.

Invincibility
Start a mission as normal. When you transport in, pause the game to bring up the sub-menu. Highlight Review Mission, hold Right, press Circle, Square, Triangle, release Right. Then hold Left, press Square, Circle, X, release Left. The word "Cheater" should appear to confirm the trick.

Cloak
Start a mission as normal. When you transport in, pause the game to bring up the sub-menu. Highlight Review Mission, then, hold Triangle, press Circle, Square, Square, Circle, release Triangle, then hold X, press Triangle, Triangle. The word "Cheater" should appear at the top to confirm the trick worked.