I liked very much the sprites and animations, there were a lot of them for a 72h jam, so good job on that! The music was also nice, specially how it interacted with the ingame progress. Indeed it was difficult (I wasn't able to complet it, for now), and I respect the choice, since I like difficult games more than easy ones. But, without compromising difficulty, I would suggest to revise a couple of issues. One is that, quite frequently, the character dies without any animation, which let the player without knowing very well where was the mistake. The other is that is unsusually difficult to properly hit your enemies in the right place. I think this occurs because of their rapidly changing movements. Maybe giving them a behaivor a bit more predictable would help to this end.
In any case, you did a beautiful game. Good jam!