The music gets quickly overwhelming, and I don't know if all sounds really fit, but that's my opinion on the matter ^^
As for the graphic, I feel like there is just no sprite for the walls appearing/disappearing when you die, and the graphic style doesn't seem unified.
I mean, that's a great job for a solo dev, especially with stuff to do on the side. I had the full week free for my game personally and I wouldn't say it's better than yours.