I was meaning to play this earlier, but other stuff got in the way :)
I liked the atmosphere- the soundscape, and the lighting are subtle, and the whole game is spooky. All the interactive elements are clearly marked, but it took me a minute to get that the music box played the music. I thought it was a book at first :)
I didn't 100% get the "rules". I know, that I had to do the things described in the diary, but there could be some indication, that I did them right. Like, after drawing a puppy, should I "show" the picture to the puppy photo? Should I do the hours in order? I didn't know that, and even though I finished the game, I still don't :)
The bloody letters didn't work for me. The ones in the first room just tell you that the house is haunted, but this becomes apparent, when you click on any door, and I think it would be more powerful, if the player just discovered that. In room with mirror, the mirror is the only interactive object, so "look in the mirror" sort of breaks the surprise.
Over all- liked it, and looking forward to playing your next game!