Scott Kaczynski’s review published on Letterboxd :
Evil kid movie displayed in a manner that could really happen. It's not sensationalized or told in extremes. There's no Macaulay Culkin, "The Good Son" crap here.
Great performances all around. I always enjoy the creepy look of Tilda Swinton. I was engaged from beginning to end.
I might go read the book. The book in written as a series of letters from Eva (the mother) to Franklin (the father). If written properly, I enjoy that style of writing. It's also easy to finish it off in a weekend.