Yep - that's not a typo in the title. The GDC XNA Challenge saw four teams of independent developers create four games in four days, completely from scratch, using XNA Game Studio Express. Sound tough? Well to make it just a little bit more interesting the developers had to code their games in the middle of the GDC foyer surrounded by thousands of conference attendee's, snap-happy media, Xbox 360 demo stations and a fully stocked bar. The end result? Four amazing games - all playable and all fun - including a 3D action RPG with two player co-op. Be sure to check out gamerscoreblog's extended coverage including links to download the source code for each project.