Varghese Eapen’s review published on Letterboxd:
After years of pedestrian horror movies this was a knockout punch. Who ever did the illustrations seen while the mom reads the book for the first time,Jesus that was creepy! There is a manifestation of guilt and grief which helped in molding her very own closet monster.Homages to The Shining,The Exorcist are nicely done. It's more than a horror movie,its a psychological hallucinatory drug trip of our very own fears.It delves into mother and son relationship.The pain that single moms go through is unimaginable. The sacrifices they make in order to raise their only child takes a lot of guts and have to undergo trials and tribulations. Essie Davis as Amelia and Noah Wiseman as Samuel deliver powerful performances. The only minor quibble was the tame climax. Still it is the scariest movie of the year and needs to be seen!!!
P.S - Kudos on the ingenious film poster!