Game Muscle

Game Muscle is a cheating device made for the Nitrome Enjoyment System. The Game Muscle cartridge appears smaller than a usual NES Cartridge. The Game Muscle cartridge attaches to the bottom of a NES Game Cartridge via small orange rectangles. Game Muscle will be inserted into the NES and also allow the game to be played.

Functionality
Game Muscle allows for the player to enter passwords that will effect the game and cause things to happen inside the game. They will not affect the game at all.

Trivia

 * Game Muscle is a reference to Game Genie and Game Shark, Cheating Devices made for the Nintendo Entertainment System and Gameboy Advanced.