**WARNING: minor spoilers are included farther down. This movie is best viewed with 0 knowledge on it's premise. I won't be including specifics but you may want to avoid those parts for the best viewing experience. Also this is after 1 viewing and is just my initial thoughts after a few hours to ruminate on it.
All the 1 star reviewers saying his is the worst movie ever probably paid half attention and looked at their phones the whole time. Or they just haven't seen a lot of bad movies. It certainly is not "the worst movie ever made," or "a waste of time." Anyone saying that is being extremely hyperbolic and unhelpful. Just resentful that they didn't like it and are wasting everyone's time with these pointless reviews. If you have nothing to say that's worthwhile or constructive then leave your one star and move on.
Now that my rant is over here is my review.
PROS: The movie has a strong opening and builds a lot of tension that left me feeling on edge throughout the first act. The cinematography was interesting and displays some great shots that kept me engaged and glued my eyes to the screen. It's certainly more interesting than the standard modern horror movie garbage that gets pumped out these days, and fans of the genre will likely enjoy this regardless of it's flaws. That being said, the 1st act of this movie is far superior to the rest and it starts to fall off after a certain event.
CONS: I have a lot of nitpicks about the movie that I'm not going to list here, but, if you have trouble suspending your disbelief then just avoid the movie. You will be taken out by the many plot contrivances that drive the main story. Characters act very stupid and not at all how an average person with common sense would act. This took me out of the movie in many situations where I was left asking "why would X do Y? Nobody would do this!!" This is just poor writing.
***Minor SPOILER warning ahead***
So the biggest appeal of this movie is probably it's 1st act reveal. This movie has a great misdirect and will make you think you've figured it out until a drastic heel turn at the end of the 1st act. This was very well done for me as I had no info on this plot before going in. Unfortunately, after this reveal I was not as invested in the plot. I kept thinking, "Wow! if they surprised me like this so early, I can't wait to see how they keep raising the stakes and keep me guessing!!" Well, they don't do that at all. After the 1st act this movie becomes very predictable and by the numbers. If you're a horror fan, you'll have everything figured out half way through and will just be riding it out as it slowly runs out of gas.
There is a lot I'm leaving unsaid as this is already a very long review. I have more pros and cons but these seemed like the most important to get out there. Watch if you enjoy horror, avoid if you don't.