Retrobattle by Andreas Remar is made to look and feel like the classic arcade-style NES games, such as Ice Climber and Clu Clu Land. Not only are the sprites limited to three colors each, but the scoring, increasing difficulty, and setup of the game makes for a challenging arcade experience that mixes various oldschool concepts. Note that playing on Skill 1 is pretty boring compared to the havoc of Skill 8, so it may seem slow at first.

http://repo.openpandora.org/?page=detail&app=retrobattle