I just watched this. Spoiler free thoughts below.
I don't know if I liked it. There's clearly a ton of talent involved. Good acting, good cinematography, some very stylish choices. It gave me some existential angst, which I think was the point in many places. And I like hard to follow movies, but this one was hard to follow even for me. I'm interested in seeing if anyone struggles with it. I think I got it figured out, but the execution was just kind of..boring to me. Like, this is a long movie, with some long scenes that IMO could have been cut down. There's an extended sequence about 1/2 to 2/3rds of the way through the film that I thought could have serious chunks of dialogue stripped away, without the overall story losing any significance.
One of the strangest movies I've ever seen. I don't know if anyone here knows a lot about well-known musicals (I know I certainly don't) but if you do, you'll probably appreciate or get more out of the film.
Also, I never felt much horror. It did often feel like something truly horrible might happen, but by a certain point I realized that it probably wasn't going to. I won't say whether anything horrible does or doesn't happen, though.