There's some cool things going on here. I liked the atmospheric intro and the background art is absolutely gorgeous. They really sell the vibe. The anime-looking portraits I didn't like so much, but that's a taste-thing, probably others will love it.
The gameplay was challenging at first but learning the boss behaviour was the key (as it should be in boss-games). The game was a bit short, starting with the one and final boss, but that's understandable for a jam game.
Cool entry!