Hey! Someone else thought of making a rhythm game! Nice work! Music choice is nice, calming, and fits in with the dream-like theme. I like the idea of casting spells only if I hit the rhythm right, but I do feel like it's a bit strict on the timing? I think some enemies got past because I didn't have enough spells to cast in that direction, or I missed the direction and I didn't know.
Would be nice to get more health, I felt like I was missing a lot because I was struggling to keep up with the arrow directions. I also agree that it was a bit difficult to keep track of 4 parts of the screen to read the incoming rhythm, since I had to move my eyeballs around a lot and it got a bit confusing and tiring.