Josh Dickey reviewed Knock Knock for Mashable. Here’s some quotes:
From this moment and through the film’s first act, Knock Knock works brilliantly from the perspective of Evan…
It’s a great setup, Hitchcockian even, but the next morning, when things go awry, they really go awry. And this is where Knock Knock lost the audience at the Library Center Theatre, as the film pivots from sexy, delicious what-ifs and restrained dread to kooky torture-porn theater at the hands of two female villains so unhinged that for the rest of the movie, their motivation — or our complete lack of understanding of it — becomes a terrible distraction.
Samuel Zimmerman reviewed the film for Shock Till You Drop. Here’s a quote:
Knock Knock again aims for that sweet spot, but it’s often lacking visual texture, suffering from a flat, stilted aesthetic. As the absurdity of both the girls’ behavior and Evan’s reaction escalates, only Armas is able to match it, her knowing smile both sly and horrific throughout. It doesn’t help that the girls’ tactics are perhaps far too worn. Izzo and Armas’ chemistry as a gruesome twosome is real deal, but their characters’ giddy psychotics are familiar. They just never push as far as Roth has proven he’s willing to go, hindering any satire of grown men playing the victim—Reeves’ final rant, sure to be immortalized by the film’s fans quoting “free pizza” comes close.
Note: In one of the webstagram photo comments, the person like the film. If I see any more viewers comments, I’ll update. These days, I take the word of movie critics with a grain of salt.
Update: Ben Kenigberg has viewed Knock Knock for Variety. He says:
Keanu Reeves’ whiny monologue comparing an act of infidelity to “free pizza” is a moment that seems destined for cult canonization in “Knock Knock,” Eli Roth’s glossy and reasonably fun update of Peter Traynor’s 1977 exploitation movie “Death Game.” The original film isn’t credited as the source of the screenplay, but this is, by any reasonable definition, a remake, faithfully preserving most of the first movie’s plot beats while adding better acting,