A lot of fun, three things really bothered me
The first is the sensitivity of the controls. It was almost impossible to just tap myself over a tiny distance, so I would constantly run into spikes just trying to line up my jumps. When you press left or right, he should start moving slowly and accelerate to full speed over half a second or so.
Secondly, the melee radius of the spikes needs to be reduced. It really sucked to barely scrape through the corner of the block, where visually, there are no spikes, and die.
Third and final complaint, after activating the last skill, flash crashed. And all my progress was gone. I'm not playing all that again, thanks but no thanks.
Other than that, it was a great game, frustrating in all the best ways. Many of the levels took my preconceived kneejerk reactions to game elements (especially floor spikes) and turned them against me...