Area 51 Cheats

Secret Rooms:
Level 2:
Shoot out all of the upper windows of the far back wall in the hangar. Another can be found by shooting all the barrels when you are in the forklift.

Level 4:
Shoot every yellow box while you're riding on the STAAR jeep.

Level 5:
Shoot the doorplate of the second door marked General Weatherby as the door is opening.

Level 7:
Shoot all the yellow barrels at the first area where the 4 purple zombies are throwing barrels on the hill.