I'm really amased about how good this game is. There are a lot of aspects to discuss,but only positive things can be said about the game. First of all, this being a game made in unity, i expected it to be much more buggy and unpolished, but it's working really good and doesn't seem to have any problem. Second, what you did is that you took a great game concept and made it even greater. This game reminded me a lot of DX ball 2, one of my all-time favorite games,but yours felt actually better; it surprised me with a lot of new power-ups and level layouts and I really enjoyed playing it.
What I feel that you shoud improve:
-a pause button would be really useful, as well as a menu accessible from there with some basic functions
-having the option of listening to some music while playing, something retro, chiptune-ish, or whatever you think it fits best
-of course, more levels would be really nice, you could try making separate "sets" of levels, like some for beginners and some more hardcore
-some newgrounds medals would also be nice, but not mandatory, still, i think they would attract more players.
Overall, I find your game amasing and I can really see that you put a lot of effort and dedication into it. Keep up the good work, you have my respect!