This is me playing the CPU at the highest level. Don't worry, it's just one game.
The graphics are quite good and the game play is also good. A lot of the player's movement is controlled by the computer (even at the ACE skill level). Without you doing anything, the computer puts your player in the trajectory of the ball but you still have to position your player correctly to play the ball (going forward or backward). I am not convinced this was necessary to implement but that's just me. Even the serve is very computer controlled, which in my opinion takes away from the game.
There's a huge tournament mode where you can enter a lot of tournaments (79 in total) and face opponents of varying levels.
I don't really know how good the computer can be. In single match play, even with the CPU's level set to the max (that would be 15), the computer player was not much of a challenge, so aiming the shots and putting spin onto the ball was not that much of an issue. Maybe it's better in tournament play.
It's not really needed but feel free to check the International 3D Tennis manual for a deeper understanding of the game.