It's okay, with a few flaws.
Overall this game is pretty interesting and has a good concept behind it, but there were a few flaws that prevented it from being as good as it could have been.
Firstly, the speed of rotation was a little too slow. Whereas I'm not suggesting it should just suddenly rotate 90 degrees in one frame, it feels a little too slow at the moment, especially as the game goes on and the spawn speed increases.
Secondly, occasionally there will be combinations of balls on the screen which mean it's impossible to collect them without either mismatching or losing the game outright. If this was intended to happen to force an increase in difficulty, it's a bad idea. Difficulty could just be increased as time goes on, rather than forcing the player to unavoidably make things harder for themselves.
Overall, this is a good idea, but it could use a bit more polish overall.