The Japanese version of Super Mario Bros. 2 was very different than its North American counterpart. Released in Japan as a more challenging version of Super Mario Bros. with new stages, enemies, features, and improved graphics, it was deemed to be too difficult for North American players. It was released for American players as Super Mario Bros. for Super Players in Super Mario Bros. Deluxe for Game Boy Color, and on Super Mario All-Stars as Super Mario Bros.: The Lost Levels for Super Nintendo.