Infinite Health P2
Infinite Health P3
Select George as your Monster. On the first level there is a sign that changes pictures. Punch it when it shows a western scene. Then when you get to San Diego on the screen when it tells you what level you're on, rapily hit the punch button. If done correctly you should see a little box saying code correct and your hidden levels name changes Carson City.
Change Character Colors
To change the colors of George, Lizzie or Ralph go to the characters select and press UP or DOWN on the controller stick or the D-pad.
Hidden Character (V.E.R.N)
To play as V.E.R.N. (Violent Enraged Radioactive Nemisis) search for a Scum Lab facility. Eat the toxic waste barrels and you will be transformed into V.E.R.N. for the rest of the stage. V.E.R.N can fly and has super strength. He can also shoot a fire ball when you press C-Down
To get to the hidden cities, rapidly punch one of the buttons below on the screen that shows your next city.
All monsters have allergies. When your monster eats the thing he or she's allergic to he or she will sneeze and it will blow down the building you are on.
George is allergic to dogs.
Jump on tanks to get a free ride. You can control the way the tank is moving. The tank will then shoot elsewhere. In a short while, the tank will explode and you will be shot into the air.
You can use those nasty UFOs for your own evil. Simply jump on top of it and you can ride it into any direction, shooting buildings and enemies. The UFO will disappear after a while.