The Stabyourself folks have created a brilliant Mario/Portal mashup as free/open software for Linux/Mac/Windows. Check out the trailer and be amazed, then play the game and watch your free time vanish!
Two genre defining games from completely different eras: Nintendo's Super Mario Bros. and Valve's Portal. These two games managed to give Platformers and First-Person Puzzle Games a solid place in the video game world. But what if Nintendo teamed up with Valve and recreated the famous Mario game with Portal gun mechanics?
A complete from scratch recreation of Super Mario Bros. with a focus on perfectly imitating the feel the 1985 classic gave us. Then give Mario a portal gun, add puzzle game mechanics from Portal and there you go. And if that wasn't crazy enough, play 4-player coop, with everyone having their own Portal gun!