Backrooms
The set design is beautiful. I really hate how the backrooms look, it sets off like a feeling of panic in me. The sound and found footage sequence is amazing, so is the first act. The characterisation in the first act is very good, it does feel and look very A24, maybe not very backroomsy. The second act (found footage-y bit) feels more backroomsy and is definitely the strongest part of the film. The third act with Mary is the weakest part of the film unfortunately, however I would argue this is because the plot moves too fast and doesn't flesh out the themes it introduces.
Honestly, i think they could have basically done the 2nd act for the whole film and it would have been like 4-5 stars.
Horrifying the set is practical.