Okay, how about these two:

It came in an earlier version of windows (or at least I think it came with it, it might not have), and it was a top-down game where you controlled a tank and fought other tanks and inantry dudes and stuff. The map you fought on was the small window of the game, and it had these gray boxes randomly placed to be obstacles. There'd be power-ups that would appear sometimes, too, and there was also a helicopter that I could never kill.

Another was this awesome version of Asteroids. There was a cool space-y background, and a lot of wierd power-ups, like one that made your ship huge, and stuff. The asteroids themselves changed their appearance every level or so, and I think one level they're giant smiley faces. I think you could play up to 4 people at once.