Wikimedia Commons/This Is Not a Test movie Celebrity Zombie apocalypse meets high school in Shudder's new horror film. Based on the popular YA novel, critics say it fails to revive the genre. March 23, 2026 AceShowbiz - This Is Not a Test is Shudder's latest R-rated zombie horror film, adapted from the popular young adult novel by Courtney Summers. The movie, which stars Disney alumna Olivia Holt, has recently premiered in theaters on February 20, 2026, but early responses from critics have been underwhelming, reflected in a 41% rating on Rotten Tomatoes based on 22 reviews.