I too, made a bullet hell game, well it is kind of like a bullet hell game lol. I have not played many bullet hell or rhythm games, but this to me felt like a difficult boss battle that put the player in interesting situations. I enjoyed the different stages of the boss since they all made me think and move differently. I didn't understand the rhythm part of the game and how I needed to dash with the beat of the music so having a visual or sound indicator would be helpful for me.