Man, I had a huge smile on my face the entire game. I found myself getting lost in the gameplay and that's not something a jam game pulls off very often.
One suggestion I have is that I noticed you could move your mouse off the screen and dodge all the fireballs entirely. I think some simple consequence or locking the mouse to the screen would fix that pretty easily.
I had a blast playing this, and you did the programming/music/assets all by yourself? Fuck man, 5 stars all around from me. I'm blown away.