Hello ! I've played Backrooms and it was enjoyable, not really scary, but those bright rooms and the sounds did the job there ! And it got me once ( well the character's scream did it, I didn't expected it, as I've seen nothing before the scream).
Now, I had one game where "friends" didn"t appear ( well they did for a minute then nothing happened, no spawn, no monster sounds, just the buzzing lights and the music ), unfortunately I don't know what happened here, all I can say is that it stopped after a minute, last monster sound I heard was the invisible one, in the back. ( And it somehow add a creppier atmosphere, being alone in those rooms :p )
Anyway, here's my playthrough (Medium, then Backrooms difficulty). It's in french, I'll add the subtitles later in the day.P.S. : the part without sounds start at 15:28 ( well, that's when I heard the last monster sound )