The True Backrooms [!]: A very well-made, and very scary indeed game, with very creative lore and thrilling gameplay.
Backrooms Unlimited: A poorly made attempt on horror and just the game, in general, is kind of bad, but can have good modeling at the time and follows the canon backrooms fandom lore mostly, but also follows the Wikidot if better. Also. the game has a good community.
The Backstage of Reality: A good attempt at horror, but the fact that the max players for literally (every) level is the default, 50, is not good. Other than that, it's a great game.
The Backrooms: Revisited: A great game, and a very interesting way of entrance. I like the unique twist for all the levels.