The title can be played in three different control schemes — traditional button controls, touchscreen control, or motion control. The button and touch controls are pretty similar, in fact, both are available without changing any settings. I prefer the button controls--I grew up with an NES and Game Boy--it's the most normal way for me to play games. While you are in motion control, the computer automatically moves your character into place, it actually makes hitting the ball a lot easier — but the computer assist takes control away from the player, which I find disappointing.
There are, as one would expect, different game modes in the title. There is the aforementioned Special Games as well as tournaments to play through, quick Exhibition Matches, and multi-player.
All-in-all, it is a decent title. It is fun, don't get me wrong, but unless you are just dying for a new Mario sports game to play, there's no need to rush out and buy it.
Mario Tennis Open is rated E (Everyone) by the ESRB.