I have no idea if the room at the end of the corridor is actually accessible or not as I couldn't access it but I do like the idea of the horror game as well as the design of the house so far. Everything seems to fall in place with the storyline and the design of the house, the objects and pictures, makes the player feel nervous while walking through the house, fearing what might happen at any point of the game. This makes me curious as to what is going to happen next in the story, what will the main character experience in this haunted and beautiful house.
The most important part of the game that the creator of the game has to work on, in my opinion, is what will be the game mainly focused on. Will it be a walking simulator, high intensity running and hiding game, puzzle-based etc. or everything mash-up together in a horror game. As long as the creator is clear about what he plans to do, the game can definitely be a success among players.
Thank you for reading my comment and I wish you good luck in your future endeavours.