Blobwars (devel, try that if you install from devel,its really cool... not any awesome graphics, just a very nice 2d platformer)
GLtron (extras?)
and some others probably mentioned before.

Edit: I noticed the in-game title of Blobwars is Metal Blob Solid, so it might be similar to metal gear solid... Not sure though because i dont really know Metal Gear Solid.