I have played many horror games making use of the idea of backrooms before and I am looking forward to see what the creator has in store for a horror game of the same idea. I was a little disappointed after finding out that the game only included the map itself and nothing else but the room with the word "hide" in it kinda makes me feel that the game could be involving a chaser and runner when it is completed.
My advice for creating a game with the idea of backrooms would be to make the map stand out instead of other beings or objects as the main thing that makes backrooms horrifying is probably the idea of endless backrooms and being trapped in such horror.
Thank you for reading my comment and I wish you good luck in your future endeavours.