PLAY FOR FREE: The Backrooms Game

Nothing but the stink of old, moist carpets, the madness of mono-yellow, and the blinding light of fluorescent bulbs at maximum hum-buzz. Over 600 million sq. miles of randomly segmented rooms. God save you if you hear something wandering nearby, because it sure as hell has heard you.

https://store.steampowered.com/app/1111210/The_Backrooms_Game_FREE_Edition/