It's been described as "the singularly most terrifying horror film in years" and "a new generation's The Exorcist".
Horror movie Hereditary has become one of 2018's most eagerly anticipated releases after scaring and impressing critics in equal measure.
Actress Toni Collette is coming in for particular praise as a woman whose family has demons in its DNA.
Bustle said it's "truly unlike anything you've seen before", while The AV Club called it "pure emotional terrorism".
The film is to be released in the US on 8 June and in the UK a week later.
In his five-star review for The Guardian, Peter Bradshaw wrote: "Hereditary tripled my heart rate, prickle-massaged my scalp, cured my hiccups - and pretty much terrified me."
Collette's "operatic, hypnotic performance seals the deal every second she's on the screen", he said.
Referring to next year's film awards season, he added: "Surely this magnificent actor will get some silverware next February."
The film's New York-based first-time writer-director Ari Aster has also received acclaim.
Writing in Vox, Alissa Wilkinson said: "The first time I saw Hereditary I yelped a lot, and very nearly crawled under my seat once or twice.
"What you feel from the start is a sense of real horror, some kind of cross between dismay and disgust, which starts out almost indefinable and builds to a (literal) crescendo by the end."
The Independent's Clarisse Loughrey wrote: "The fact Hereditary is being (rightly) talked of as one of the most singularly terrifying, singularly disturbing horror films in years speaks to its unique sense of mood, reports BBC.
"Secrecy, guilt, anguish: Hereditary breeds its own phantoms. Ones which like hang around, to boot. Weeks later, you may step into a dark room, and that chilled feeling will come rushing back: am I truly alone right now?"