This game reminded me a lot of "BOXBOY," a game on the 3DS eShop. Any relation, by chance?
Anyway...
Hollllllyyyyyy fuck this game is brutal. The challenge scaled very smoothly and nicely and then just skyrocketed into a real mindbreaker. I really enjoyed it and despite lots of frustration I never felt mad enough to cease playing, so props to the creator on that. However, the lack of an ending was really really rude. Maybe I was supposed to play again, since the start of the game was different than before, but I was mentally done with the game.
I really enjoyed the gameplay and the development of the character, but the fact that there was no real ending (as far as I can tell) invalidates all of that. I enjoyed the game enough for it not to bother me too much, but I feel like it's something I should be bothered by.
Furthermore, as I said, while the gameplay wasn't ragequit inducing, it felt sorely unfair at points. The traction really screwed me on some specific jumps and positions I had to take to proceed, and it didn't feel like it was my fault. Furthermore, whenever I would change face, occasionally I would slip in between platforms, making me feel like I wasn't entirely in-control of what was going on at times.
Despite all this, I really enjoyed this platformer. With a few tweaks, it could easily be one of my favorites. To go even further, with a little more work and time, this could be a real masterpiece of a story and game. But that's up to you. ;)