Herb Gallow’s review published on Letterboxd:
Perhaps my greatest fear is that I'll be tricked into wasting two hours of my life watching a Juggalo murder cosplay, and that kept me from watching this one when it hit the streaming services. Fortunately, that fear was unfounded. This time.
This is quite the achievement for Damien Leone, who wrote, directed, edited, and did the special effects, which were noteworthy here. There's a fine line between summoning the spirit of the beloved 80s slasher film and looting its corpse for parts, and Terrifier walks the correct side of that line. Paul Wiley's score sets the right tone without feeling overly nostalgic, the reliance on practical effects from the initial scene provides the look without having someone dance-wave a "hey, remember your childhood" sign at me. The film has a workmanlike, reverent approach to the slasher formula that is charming in its competence.
Mr. Leone has constructed a very solid foundation for the film's main draw, which of course is Art the Clown (David Howard Thornton). The unrestrained, fucking ridiculous glee with which Art conducts himself throughout this film is infectious. Choosing to go the pantomime route heightens both the humor and the creepiness of the well-established evil clown thing, and Mr. Thornton is quite the able practitioner. Even under the layers of makeup and blood, he has an extremely expressive face that would be at home in a compelling silent film, and if nothing else Mr. Thornton should have continued employment prospects from the inevitable line of sequels that this will produce. He also brings a physicality to the role that sells some of the more flamboyant set pieces, especially the signature bisection scene. It's not often you can up the ante on films like Bone Tomahawk.
I suspect that the second time around the act will have worn thin, but for now, this is a very respectable entry in the genre and a promising start for Mr. Leone.