It is a multiplayer platfomer/shooter made in XNA.  We started with a pretty bare bones engine -- probably not a bad idea for a first time developer as I learned a lot and got to work on just about all aspects of the game.  The concept is pretty simple: Pyro has a flamethrower, Cryo has a freeze-gun.  Pyro can burn things down and melt ice.  Cryo can freeze things and put out fires.  The pair is stuck on an alien ship, looking for a way out.  Here is some old gameplay video: