Congrats on almost reaching your funding goal! This game has a lot of potential, and you've done a great job on it! (Video below if anyone wants to watch!)
The whole atmosphere and house was well done; it was dark, there were spooky sounds and it was generally a good spooky environment,
That being said, I personally thought that there were too many doors in the game; their main purpose was to slow the player down and to anticipate a scare that might happen. And it sort of had the opposite effect, where the player would have to open doors every few feet, it kind of gets boring after a while. My suggestion to this would be to design an actual house and make the player roam through that, than make it more of hallways that they have to get through.
Also, the mechanic of opening the doors wasn't that great (I had difficulties when I first got in the game.) Maybe doing it the Outlast way where you can press a key to fully open the door or hold a key to slowly open it would be a good idea? That way, players have a choice and they don't have to slow down and manually move their mouse in order to open the door.
And one other thing I would suggest is to make the monster that is initially shown more prominent. The loud noises and fringe effect as jump scares were mainly scary because it was sudden and loud, but not because they were scary. You've built an interesting character with the notes and making the monster scary because of that is a great way of tying it in with the whole game and adding to the scary and spooky vibes!
The above are just my personal thoughts and suggestions, I do know that coding and game dev-ing is hard. But it was an absolutely fun game to play! The story you build with just the notes alone, was (I think) amazing and you have a knack for story building and climax.
The house had spooky vibes and looked great. The sounds were well done as I mentioned, the spooky house sounds added to the subtle scare of the game and helped raise the fear a little bit. The shadows of the house was also well done! I almost expected a scare at every corner because things were pretty dark and thought something might happen because of the sounds!
Oh, and one last suggestion is to change the keys for using items and leaning. I found that the defaults for using the torch was '1' and leaning was 'Y' and 'X'. Maybe making torch as 'F' and leaning as 'Q' and 'E' might be better because that's what other games do and is more comfortable to the human hand. Or maybe have an inventory system where you can quick select three or four items and store things which you won't use, might also be a good idea!
But yeah, this game can really be well done and it's a great start so far! I hope the updates and everything go well and can't wait to play more as you finish the game! Good luck and good job on a great demo so far! (Also, sorry for calling it a Resident Evil type game, I might have mistook your game for another? Because I thought I remembered the preview photos having a gun and some RE type monster.)
P.S: I found a space in the ceiling at the end of the game where one could see into the sky. (Just thought that you would like to know about that.)