The Nintendo Game Link Cable is an accessory for the Game Boy line of handheld video game systems, allowing players to connect Game Boys of all types for multiplayer gaming. Depending on the games, a Game Link Cable can be used to link two games of the same title, like Tetris, or two compatible games like Pokémon Red and Blue. Games can be linked for head-to-head competition, cooperative play, trading items, unlocking hidden features, etc.