I figured my notes from reviewing the games might come in handy, so here's what I wrote about your game as I was playing:
Excellent work! Makes very good use of sound effects and music to expand the experience of the game, very nice and big too!
The unlocking of abilities that make the enemies go from obstacles to helpers was a great touch, it really did give the levels that metroidvania style “transformation”.
I would perhaps want a slightly longer invincibility period after getting hit, i got bounced around pretty good by the monkeys and the “fish” a couple of times. But all in all it was a very pleasant experience.