Melgashi,
do you still have the previous version ?
The last version doesn't have the launcher anymore, so it's not possible to edit the joystick input, so if you have messed them up, you can't fix them anymore...

Else, is there any button or axis working from your controller ? If not, you may need to turn on XInput support to allow support Direct Input in your drivers config panel.
Davide Menez,
flying player fixed for the next update, thanks to your report !

For the left-handed racket issue, I need to do some calculations to put it back in the correct way and hopefully I'll find the time to do it before the end of the day.
Sali_O296 & Davide Menez,
what is your controller ?
It's working fine with my XBox 360 controller.
Try to open the "Tennis.ini", and check you have this line, under [Controller] :
JoyDeadZone= 0.35
It shouldn't be 0, else the player might move constantly as you have noticed.
How to find the .ini :
topic19-32161.php .