Here's a little (poor) single player action from War in the Machine. Should see this first at the PRGE.
You control one of two bases in the center. You launch and steer your ships into the enemies. The C button stops your base but renders you invulnerable and recalls your ships. There are 8 possible wing, gun, back and front configurations for a total of 4096 possible enemy shapes. Movement strategies are randomly generated. The boss enemy takes the current highest rated movement pattern. Red enemy planes and rockets are invulnerable. Once you meet the quota of kills the timer resets and enemies get tougher.
This is a single player run. 2 players can compete for the best score BUT the game ends if either runs out of shields.
After the PRGE this should be available from Good Deal Games
http://www.gooddealgames.com/
UPDATE: I forgot to mention this is chromadepth friendly. meaning, if you have those Crayola 3D glasses things should pop out. Blue things are in the background, green/yellow in middle and orange/red in front.