We've been waiting all weekend for Stabyourself.net's launch countdown to tick down to zero, and now the developer's much-anticipated mashup of Mario Bros. and Portal has arrived on virtual shelves. As billed, Mari0 is a "complete from scratch recreation of Super Mario Bros.," except Mario has a Portal gun now. The game is free, cross platform, and open source, so there's no reason not to try it out. However, if you really want to get the most out of it, you might want to track down some USB controllers so you can get some local multiplayer going. Now, if you'll excuse us... we need to shoot Luigi at high speed between some inter-spatial planes.