To use this trick, you will need to have obtained and bought the Metal Generator. Then you need to beat at least one maverick so that the Noah's Ark stage will be unlocked. Now, return to the Noah's Ark stage using any character. Take a rubber band and rubber band the left dual shock stick in the Left position so that your character runs to the left side of the screen and just runs against the side of the screen constantly. Eventually you will start generating metals every few seconds. Now just turn the TV off and let that run overnight or whatever. Within a few hours, you will have almost 100,000 Metals.