Cool game ! The multiple boss fight were pretty cool. My two negative things would be that it took me a while to understand that I had a double jump wich is crucial for the first boss fight, so some kind of simple tutorial would be nice. Also the range of the attack is very small, so I would often get it by the boss because I'm going toward it and the range is small enough that I would hit them but get hit back right away.
Cool game ! Cool concept, I played to the end, was fun !