I loved your game!
This idea simply could work heavenly, and sell a lot in the market.
I would definitely work in a project like this, good job!
Now for the actual deliver:
We need sounds in the game, if you can't, try to at least set some bg music to let some atmosphere happen.
A polish would be nice in the game, a simple one that I would do is a simple trail in the ball, and particles bigger when you score.
I couldn't play multiplayer, but I imagine it would improve a lot...
I don't know how your space are, but this project can easily be marketable, so think about it!
Good job!