Game Boy
Though Nintendo never released an adapter for playing NES games on the SNES, the Super Game Boy adapter cartridge allows games designed for Nintendo's portable Game Boy system to be played on the SNES. The Super Game Boy touts several feature enhancements over the Game Boy, including palette substitution, custom screen borders, and access to the SNES console's features by specially enhanced Game Boy games. Japan also saw the release of the Super Game Boy 2, which adds a communication port to enable a second Game Boy to connect for multiplayer games.