Well, that was something. I have to admit, I have a very bad musical taste and a poor understanding of music, so any musical challenge in a video game is almost always exponentially harder for me. This one was not an exclusion. I clicked on some ghosts many times, and then a musical sheet appeared, and a melody played. That was it, I was not even able to say if I won or lost, and what results my actions had.
I say all this not to say that the game is bad, just to highlight what a strange experience it was. And although I felt like I missed something, I still kind of enjoyed it; the strangeness of visuals, spooky sounds, and cryptic mechanics all added to the sense of mystery.