I thought the idea of spawning with a new ability was really cool. The only problem was it took all the challenge of any enemies out of the game. Also if you killed some enemies it was impossible to continue in some points, and so if this would be the case having a restart button would be good.
I think having the abilities not stacking would also be interesting, that way you have to choose which one and it makes it more of a puzzle. (on't know if that's intended or not because it stacked for me)
Definitely shows promise and would love to see it with some more polish