I'm impressed at the level of polish! Multiple difficulties, a soundtrack that works for the game, a responsive dialog system, and good use of colors and post-processing. This is one of the best I've played in this jam. I personally didn't really like the boss fights, but I just don't really like bullet hell games.
I think the boss fights would benefit from zooming out, showing the whole boss all the time.
The safest place in the boss fight is almost always as far away as possible, which means I just end up shooting in the direction of the red arrow.
Speaking of the red arrow: great addition to the game. It's quite easy to miss a room, so having the arrow point to the nearest enemy really helps keep the pace up. I never got stuck, thanks to the arrow.
Well done!