I think TE is really good game now. There is just need to improve some detailts to make it perfect.
First of all, you should work on what the player sees right after starting the game. I mean the default game setting (players, camera setting, or various graphic elements - this is very important for TE marketing.
I thing something like this :..................................................
- it would look much better than what is currently the default. Shows the strengths of this great game.(Personally, I would really like to have more options for 3d camera settings. (set it like in this video is impossible)
It would also be nice to add some important tennis moves for more reality of game. For eg.when the player maximally reaches the ball.
Something like this:
Details such as adding steps animation when changing the player's position during the service (right left)
It is currently the best tennis and the competition is far behind. Refining the details will make the game even more "professional".
I am a big fan of this game, I have been following with interest for many years (from 1996 and 1.3 ver)!
All the best!