I think what makes the original idea of the backrooms so unsettling is that there is absolutely nothing in there. To fill it with "scary" enemies is doing the concept a disservice.
Perhaps if the game had you wandering around with just this unsettling atmosphere, not knowing if anything was with you, and you being alone with your thoughts, quietly going insane, then I think this could be quite a good concept. As it stands though, it's just a generic horror game.
Maybe take out the enemies, and have some other objective that expands the "world" for lack of better words. Maybe you look for remnants of others that had been trapped in the backrooms, perhaps there may be no end game and you're just exploring a story that you piece together.
Maybe it doesnt even have to be a horror game in the traditional sense, maybe it could be a psychologically unsettling walking simulator. So many concepts like these never get realized to their potential. A procedurally generated map would also be a great idea used here, though I'm not a programmer and have no clue how difficult that could be.
Overall, I respect the idea and think it could be quite good, but at the moment it falls into the traps that most modern indie horror games fall into.
P.S. All of my criticism was meant to be constructive and no ill will was intended, I like the concept and would love to see this come out as amazing as I think it can be. Have a nice day if you managed to read all the way through this, I tend to be quite long winded.
EDIT: Sorry, I'm new to itch.io and forums in general and did not notice your ideas board.