This was great! There was obviously a lot of effort put into every aspect of this game, and it shows. I really like how collecting each music note added another instrument to the music, that's a really cool touch. Once I noticed that I went out my way to collect any that I saw.
Small bug I ran into: a few times when I died, I respawned outside of the playable area and would die whenever I tried to run back on land. Restarting the level fixed it. I wasn't able to figure out how to reproduce it consistently so I'm not sure what was causing it.