Wow! I just saw a let's play from the Alpha Beta Gamer' youtube channel and I can't wait to play the game for myself.
I especially love the story and the writing, the dialogues are good (which often is the thing that suffers the most in horror games). The ambiance and creepy effects throughout were really cool, the way the light changes and the reaction of characters for example.
I loved that the characters had little reactions to your actions, it made the whole thing more real.
The only thing that is bugging me is the art, especially the portraits (when the characters speak or when you meet them), it looks amateurish. Right now I think it distracts a little from the whole experience which, aside from that is amazing. The small animation though was creepy and did a great job.
[small spoilers for the demo]
I surely will have nightmares about bleeding eyes and puppets. The game's mechanics are fun. That you had to solve puzzles whilst distracting the mansion's staff and them wanting to kill you instantly, added a cool stress level to it. I especially loved the small notes gained during the game, which helped to solve the puzzles and at the same time added a strong element of mystery each time.
In short, I love it and I was hooked by the story, can't wait for the game's release!