This game as a potential, there is alot of details to rework but still good and its the first time I see a really good horror game concept like this, almost innovating.
Detail to rework
At the beggining, when we are at the outside of the school, walking sounds are a bit poorly done ; I only hear it when I press A,S,D but not W to basicelly walk (I have a AZERTY keyboard so I changed keybinds to Z,Q,S,D).
Second is the rain ; there is not so much cloud at the sky to rain this much and rain anyway, so just add a sky full of clouds.
Aesthetic effect with the rain can be better but it still amazing for now, other bugs and details forgotten are more important to that tiny detail and its my taste, and thats what makes the game so good and almost a innovating concept.
I think there is something wrong with the camera system, you can literally see writtings throught everything, and if its not in my taste this is not a good idea.
End of the game
The end of the game is not really a good one but like you said its a short game developped on one week so I can't really say it's a bad one.
Thanks for making this good game anyway !