I'm going to be honest, I said this in the video (below if anyone wants to check it out) and I have to say it again: If someone told me that this was a big budget game that was made by a large game company, I would not question it.
Let me start off by the sounds. The sounds very absolutely terrifying and the matched and even enhanced the surroundings and environments perfectly. You've utilised sounds really well and made the game ten times as scary with them, and it's amazing. The creaks, groans and random sounds of the house were just amazing. Though that's where it becomes its own double edged sword; there were too many sounds being played at once. An example of this is when I started to read the letter where the missing painting was supposed to be kept.
The sounds, as terrifying as they were, were way too distracting for the concentration on the task at hand to be kept. The other problem about using too much sound is taht the jumpscares; when you take the photo of th chair and the painting and the lady in the corridor were not as scary as they could be. This was because the player would have gotten used to the loud noises constantly playing, so the jump scares were not that effective. It's probably just me being very nit picky, sorry about that. But sound was one of the selling points and just made the experience just that much scarier.
The other thing were the graphics, it was top notch and was really well made. Even the little things like the fringe vignette and the shadows added to the experience.
The level design was great and more than a lot of fully released games would do. You guys thought it through really well and implemented it really well as well.
One other suggestion would be to make it more obvious where to take photographs. Maybe add like a voice line, or thing you need to photograph a little lighter than the rest of the environment. It was a tad bit confusing as to what I had to photograph to progress through the game.
Sorry for this really long review, but it was overall an amazing game demo, and cannot wait for more! I wish you luck for the next release and for future games! Keep it up!!