Just updated it, with some collision sounds ... not ping-pong ones, but nice anyway.
At first I was wanting to get some objects in the field, so the ball could bounce against it ... But if these objects weren't spheres or plains, the collision wasn't physically correct anymore. I'm still thinking about it.
To download the new version, it's the same procedure as above :
Besides, the speed increases if you get a level higher.
"Begin at the beginning, and go on till you come to the end: then stop." - Lewis Carroll