Very fun! Unsure if you're unable to click the mermaid to hear the song after you've already failed once, though, cause that was the end of my first run 😭. It'd be nice if there were more noticeable differences between the shells towards the end, cause you need very trained ears, or at least lucky trial and error, on the last couple of levels. It'd also be cool to have more shell slots to reproduce longer melodies!
Overall, loved this game! The mechanics are simple enough to understand easily, but there's a lot you can do with it! Both the art and music are very nice as well!