Hard Vacuum!

Player versus Player or AI.  Zap the filthy Other before he gets you!  Or something else does.  Best of ten wins the match, but the level changes each time a point is scored.  Yeah, it's dangerous in outer spaaaaace!

You wouldn't believe how old this code is.  Using the Allegro.js library by Sos Sosowski, which in turn is a port of the old school Allergo library by Shawn Hargreaves.