I really like this game. I couldn't bet it right now which is good i like hard games and will definetly come back to it.
The biggest issue i have is the way you reset after death. Might be just me but on one level a bit into the game i can do the first 5 waves without a single hit but die on the 6th one every time. So i spend a long time on things that are easy to me just to get a single chance at the hard part, which can get annoying after some time.