My friend and I just released a Backrooms generator, it generates maps procedurally through geonodes and can export it in a click for game engines
Every Backrooms footage you see in the video above has been rendered directly in Cycles without touching anything, I simply animated a camera, a flashlight and a dirty lens, then added a CRT effect in AE
Geometry, lighting and textures are direct results from the add-on and haven't been altered in any way
This generator comes with a simple panel in which you chose your type of backroom from 4 styles (lobby, poolrooms, parking lot and hotel) and just have to click on generate, then you can select the mesh created and adjust it with goenode sliders to change the size and the density of each type of room with the environment
All assets are low poly and game ready, it works like a charm in both Eevee and Cycles, and all assets falls under CC0 licencing meaning you can use the generated maps for monetized content, professionnal assets and even games, as long as you don't simply try to sell the maps
There is even a game export function in which you can chose presets between Godot, Unity and UE
If you would like more info free to ask or check it directly
Hope you'll like it!