Hold [Ctrl] + [Option] + [Command] when selecting the number of players. A level select window will appear to allow any level from 1 to 20 to be selected.
Cheat mode
Enter one of the following codes to activate the corresponding cheat function.
Effect Code
Use one life from other player to resurrect self 1ammybrother
Extra TNT box 1ambubbus
Extra lives 1amcheater
Kill everything on screen 1ampesticide
Unknown 1amfrostydog