Absolutely beautiful graphics, great audio and clever level design.
I especially like the first level which makes sure you know the core mechanics before you go on to the rest of the game. I'm not a big platformer player, so it did take me a while to figure out the down+jump to go down and that I could jump onto my axe once I'd thrown it. Some graphical hints might help with that (like you have for the controls on the first screen).
Great work!