I just finished your game. Loved it! The concept was fun and made the game more interesting. I also really enjoyed the little boss fight at the end.
My only gripes would be the controls and music. It may just be how I am, but I felt using the 'Q' and 'E' keys felt a little uncomfortable. That's more of a subjective opinion, so feel free to take that with a grain of salt. The music, however (although pretty faithful-sounding) had a very short loop that was extremely noticeable.
Beyond that, I was very pleased with what I played. I loved the style, and everything worked as it should. I ran into zero problems. Once again, the concept was a good choice. Great work, and thanks for the experience! :)