Jason Pettus’s review published on Letterboxd :
I was lucky enough to have instituted a complete embargo of information in my life regarding the horror film Hereditary, once I started seeing friends at Letterboxd gush about it and realized that I would probably be seeing it soon myself; so I want to return the favor and be very careful about what I mention here in my own review, although I enjoyed it so much that I at least want to say a few things about it. Primarily we should praise Toni Collette, who I didn't realize starred in this until I sat down in the theater and started watching it, a gifted actress who excels in everything she's in, and who here does such an amazing job at portraying a woman who is slowly being driven towards a complete mental breakdown.
Is she in fact hallucinating all the crazy supernatural stuff going on around her, especially given a family history of a mom, dad and brother who were all classified as violently mentally ill? Without revealing any spoilers about the answers, that setup is the other great touch of this movie, because it opens an entire Pandora's box regarding interpretations of the plot, deeper messages from director Ari Aster about mental illness, and extremely disturbing implications about the legacy of dysfunctional families from one generation to the next. And I love that all this is presented to us as a series of clues like a puzzle, the film dropping in subtle hints and easter eggs all the way from the very first scene to the very last, beguiling and mysterious as the movie actually plays but, unlike a head scratcher such as Donnie Darko, with everything neatly if not devastatingly and terrifyingly explained by the end.
That's perhaps the most satisfying thing of all about Hereditary, and a big part of why it's getting so much praise; it delivers all the thought-provoking weirdness of an obtuse David Lynch film, yet nicely comes to a very simple and explainable finish by the end, unsettling in the extreme if you take an hour afterwards to really unpack the implications of everything that transpired, which apparently a lot of mouth-breathers out in Multiplex Land didn't bother doing, which is why you've generally been seeing bad reviews from suburban audiences about how the movie is "too slow" and "not scary enough." If by "not scary enough" you mean that no evil clowns jump out from behind corners while the soundtrack volume suddenly goes from zero to ten instantaneously, then yes, I agree, Hereditary is "not scary enough" for the sub-literate troglodytes who need their scares broadcast to them in the most patently obvious way possible; but if you like your horror smart and festering, burrowing under your skin and giving you the heebie-jeebies while laying in bed in the middle of the next night, then this is exactly the ticket for you.