I have a thing for spooky mansions, rainy nights and Moonlight Sonata so I was definitely attached to the game. I loved the ambientation, the mood and the premise of the story.
Oh, and the art is truly beautiful! I'm not sure why (might be just me) but Heitor's character design gave me the same vibes as Howl Pendragon, and who wouldn't love that? :D
As a side note, since there's an actual piano that is played in the game, I was a bit surprised that the music wasn't diagetic. I personaly feel like it might be a nice thing to play with (maybe it could stop when the text say so?). Anyway, there's clearly a lot of effort in the game, and it's gorgeous ^^ good job!