Fan made Mario/Portal hybrid game
Mari0 is a fan made platformer based around the original NES game. Take on the classic Mario game with a portal twist, including online multiplayer and level creation.
Not just pipes
Developed by Maurice Guégan of stabyourself.net back in 2012, Mari0 was created as a light-hearted fusion of the Mario and Portal games. The game features a full recreation of the original Mario game with new playable characters, control scheme and weapons. Alongside the basic jumping and mushroom mechanics, a basic 2D version of the portal gun can be used to create new openings around the classic levels. Also included are online co-op and level creation tools. The game became something of a cult classic with fans enjoying the new angle and ability to play with friends, earning a place as one of the first Youtuber-embraced titles. Available as a free open-source download, Mari0 continues to offer a silly gameplay experience best enjoyed with friends rather than as a new platformer.
Mari0 is a wacky "what if" scenario made by fans for fans. It is a happy surprise that the usually-litigious Nintendo has allowed the game to exist for so long, making it a noteworthy classic alongside the official releases.