A very well-made game. The graphics, music, and sound are very good. The gameplay is also well-defined.
The inertia of the character feels kinda weird, like, it's too slippery everywhere. Also, I would like to use Space for jumping and to use both of my hands while playing. The final boss was a bit anti-climactic but I think you just didn't have time for that. Also, the wall jump was barely needed throughout the game.
A great platformer overall. A few tweaks and you'll have a great base for a great game.