I played through to level 6, didnt get all the upgrades. Was fun, nice demo good job. Only negative thing ill say is i couldnt really feel the impact of the special balls, it added some nice variety to the visual aspect but other than that they didnt feel very unique compared to a normal ball. Occasionally i could tell that like the weighted ball fell faster or something but not much other than that. I think either make them do some more unique physics stuff or at least add something at the end of the level that shows how much each ball added or something i dunno, good luck