Great job! This was fun and decently challenging, I like the overall presentation too.
My one complaint is that I wish that it was a little easier to tell when you actually take damage, like if the player flashed or there was a sound effect on hit or something. For some of the faster attacks (like the swords that fly out of the armor boss) it's pretty hard to tell if you actually avoided it or not without watching your health-bar.
Overall though, great job!