The theming was easily my favorite part! The music (seriously, what a great loop for this), darkness, monsters, old wooden planks, etc all add to the mood emphasizing the "dark" in "dark arts". Also, obtaining powers as you progress is a great way to create a feeling of accomplishment throughout the game.
As for feedback, I didn't notice a health bar when I went through it, so it wasn't clear to me if getting damage actually had consequence. Also, I found that even though I could attack, I never felt I needed to, and instead just tried to evade enemies.
Awesome entry!