Someone who saw Knock Knock at one of the recent press screenings left positive feedback on R/Movies. You can read the entire comment at the link. Highlights are below.
Although the dialogue is campy, the performances were great. Keanu Reeves as the helpless victim was such a joy to watch, and you really can’t take your eyes off the two femme fatales (Lorenza Izzo & Ana de Armas).
The plot is over-the-top and farfetched, but it’s surprisingly very entertaining. This was one of the first press screenings I’ve been to where the entire theater was laughing.