The art style is excellent, and I enjoyed the puzzles/bone "drawing" mechanics.
The dialog & tutorial added a lot, though I wish the necromancer had clarified that he keeps the weapon/tool that he used last, or some UI to show the currently equipped item. I kept redrawing swords the first time I fought the slimes!
More could have been done with the bone-gathering mechanic, since it is only used once at the start. As some other people have mentioned the controls were a bit clunky.
I nearly missed the sound and music. I had to crank my volume up massively to hear the music at all, as well as some of the sound effects.
Overall I liked it. This was a fun zelda-like proof of concept, and could be expanded upon to be a full game.