Press [Alt + [Backspace] during game play, then enter one of the codes.

2000 Electricity - zap me
5000 Plastic fantastic plastic
Random team colors on map color me stupid

To bring the little cheat box press [{ALT]}+[BACKSPACE] and type god mode as: Fantastic goo. To get infinite plastic first press the same keys [{ALT]+[BACKSPACE] and type :Blints is dead.