Tennis. What do I say about Tennis (other than that I am a real nut for the stuff when it comes to playing the sport!), other than that, it is tennis!
The graphics are solid and convey the sense of play well. You can serve, lob (one of my faves) and smash on forehand or backhard quite easily. One of the biggest problems for many sports sims is the lack of response in the joystick, not so with this one.
The match is the best of three sets, you can choose from five difficulty levels and select singles or doubles options. Tie-breakers are played at six games all and there's even a little cup sequence at the end for the winner.