This last weekend I competed in the HackPoly Hackathon. In just 24 hours without any sleep, 2 cal poly students I met at the event and myself created a multiplayer game in java from nothing. Here is a link to go check it out and download it to play for yourself. The game is open source on github.
http://devpost.com/software/networkgame
https://github.com/ksbdude/Pow
