User Summary Super Mario Bros. Special was the first licensed sequel to Super Mario Bros., released a few months before Super Mario Bros. 2 in Japan. It was not developed by Nintendo; instead they outsourced development to Hudson Soft, who made gameplay changes, introduced new power-ups and enemies from Donkey Kong and Mario Bros., and created new levels instead of using existing ones. In addition to its unusual nature in comparison to the other games in the series, Super Mario Bros. Special is known for its difficulty, which some say surpasses the notoriously difficult Super Mario Bros. 2 (AKA the Lost Levels).