Go to level 3, and near the end (before the elavator), there should be some platforms with two ogres on them above you. Kill them, and a cage behind you will open up, revealing armor. Wait, there's more than that. Shoot the wall behind the armor and there is a warp. Go into it, and you are warped onto the platforms. Go to the platform with some missles on it, face your right, and shoot the wall. This reveals a secret hallway with a warp in it. Don't go in it yet! It's a trap! The floor will open up, revealing lava. Sidestep to the right and run to the warp as fast as you can. You'll be taken to a secret level, Zigirat Viritgo. Only level four, and the game is playing with your mind! There is 0 gravity in this level and a tomb!

Turn on god mode, then turn off target mode. Hit a monster to make it chase after you. Run behind another monster. The monster you hit will damage the other monster and they will begin to fight until death. Grunts are the only monsters that will fight against themselves. If the monster you hit wins it will keep chasing after you until you kill it. If the other moster wins he'll stay in his orginal position until you hurt him.

Enter NOCLIP at the password screen. This enables players to walk through walls.

I think that Midway may have not known about the other exit in level 25. Why? Well turn on god mode and level skip and go to Shub's Pit grab the Rocket Launcher. If you have played the PC version you should know how to reach the other exit. If you don't know how I will try to descibe how to reach it. Get the Quad damage hidden in the room you get to by jumping off to the small ledge at the top of ramp. Teleport out to the Island and Quad Rocket Jump towards the wall over by the spot where you climb out if you happen to fall in the lava. The game will say completed and will start to say BUILDING as if there is another level. But nothing more happens the game is locked up. In the PC version this normaly takes you back to the start level. Did Midway miss this exit when porting over the game too bad they did not use this to hide an extra level.

In the password screen type QQQQ QQQQ QQQQ QQQQ until it says "incorrect password" , then go to the options screen and on top will be "DEBUG"

Debug mode includes: Warp to levels, weapons on, god mode on, and targets.