Very much like the gameplay. It is a bit difficult after a bit, but maybe you have to get used to it. However I love that it's not too easy (as per your response to my difficulty question in the other thread).
If I can, a couple of small suggestions:
-maybe every 'x' levels should be a hard-coded and not proc generated (like a boss fight or something)
-aesthetically maybe the 'powers bar' at the bottom needs another background border grouping them all together, and perhaps rounded corners?
(I realize this is just cosmetic and subjective based on taste)
I like the original concept as a whole, and it's very well executed. Well done!