 There was a gold (black in PAL regions) cartridge with a switch at the bottom in order to be compatible with the American and European hardware.In Europe there also was a version where the cartridge was in the form of a plug through cartridge, a cartridge you plugged on another, normal NES cartridge and then inserted it in the machine.It was also released as an add-on to the Aladdin Deck Enhancer created by Codemasters.