Played this on windows with a mouse; I can see how well this works for touch screen interfaces, this would be really neat on a giant touch screen with multi-touch and different users, like if you had 2 teams one on either side of the board; or everyone for themselves 4 player mode...yeah this is a fun submission - I really enjoyed this :)
Oh and the visual effect of stretching out the balls when they go faster; and the merging; really awesome - one thought would be to offer some sort of indicator on how many points a ball is worth before shooting it for the goal; I dunno if it would make sense to toss numbers in there or if that would just clutter things up : just a thought : loved this!