**3/10** - Maybe if it was a YouTube video it would've been respected more.
Not sure why some reviews say that this is "faithful" and "not just jumpscares", because that's not fully accurate; It very much operates like a standard A24 horror movie. That's not to say that they do a bad job, but you can tell that this was made by, and made for, people that grew up with FNAF and the backrooms themed cheap game adaptions. It's pretty unrelated to the concept of the backrooms from the original 4chan postings. Sure, the writers may have tied in some deep easter eggs here and there that somewhat show that they did their pop culture "research", but even that is a depature from the source material.
You can just skip around and watch the found footage parts for the scenary and visuals which is mostly pretty great, save for the injection of fnaf vibe monsters.
If you appreciate the scenary, concept and vagueness of the original source material from 4chan, you can probably just find all the relevant clips already on YouTube; watching this is unecessary for that.