Imagine Game Boy Tennis, only made on a lower budget in a fraction of the time, and you'd pretty much have this. I really don't have much to say about this game. It's tennis. With the added bonus that you quite often can't see the ball, thanks to the Gamate's crap screen. The only particularly notable thing is the amusing face your character makes when you score a point, but I can't get a screenshot of that.
(click for hi-res versions)