Shudder’s new R-rated zombie horror movie adapted from a popular book has thus far failed the critical test according to Rotten Tomatoes.

High school kids must go into survival mode amid an apocalyptic zombie attack in Courtney Summers’ YA novel This is Not a Test, which has now been turned into a horror-thriller movie starring Disney’s Olivia Holt.

Early critical returns suggest Shudder’s R-rated book adaptation may not satisfy horror fans’ hunger for zombie action, as the movie version of This is Not a Test debuts to just a 41% rating on Rotten Tomatoes, on a healthy sampling of 22 reviews.

The zombie genre feels like it’s gotten stale, critics are saying, and This is Not a Test adds little new to the mix that is interesting or innovative. The Adam MacDonald-directed film is being knocked for a lack of technical polish, and though some reviews acknowledge the story’s ambitiousness, they argue that the movie’s cinematic shortcomings prevent it from paying off.

Star Holt is given some praise for her performance, but reviews note that the supporting cast is generally not up to her level. A handful of positive reviews give the film kudos for its attempt at combining zombie horror with coming-of-age story dynamics, though even the relatively good reviews concede that the end result doesn’t quite gel.

Screenrant’s own This is Not a Test review singles out Holt for plaudits, saying that the star “beautifully delivers the genre candy in the form of visceral screams and trembling vulnerability.” However, the review agrees with critics who think the film falls short of delivering on its ambition to say something new within the confines of the zombie genre and its well-worn tropes.

Screenrant says, “The film circles around heavy themes of trauma and survival ethics without landing on a coherent stance.” The review adds, “In the end, one is left wondering what exactly audiences are meant to take away from the This Is Not A Test experience beyond stylish blood splatter and a sharp punk-rock soundtrack.”

Stylish gore and a good soundtrack may be enough for some die-hard zombie fans to sink their teeth into, but critical consensus thus far suggests that This is Not a Test lacks the ingredients to satisfy those who think the zombie genre can do more than just deliver the same old familiar thrills and chills.

This is Not a Test released in theaters on February 20, 2026.