I loved the concept very much, thanks for the experience! Art is good, so is music, controls are great. Bosses, though, felt a bit weird: Mephisto can be cheesed a bit since I can just stand outside of spinning area (to not get hit by random things on the stage) and Macbeth turned out to be even easier to beat (although she goes second so I expect her to be harder on me).
Other than that - very impressive! Waiting for the 3rd boss!