Screen Rant calls it "an emotionally compelling and exciting film" and "an exciting, beautiful, and thought-provoking adaptation of VanderMeer's novel". The Guardian calls it "unnerving" and says, "it will shock, fascinate and haunt audiences".
Roger Ebert's site closes with this:
“Annihilation” is not an easy film to discuss. It’s a movie that will have a different meaning to different viewers who are willing to engage with it. It’s about self-destruction, evolution, biology, co-dependence, and that which scares us the most—that we can no longer trust our own bodies. It's meant to linger in your mind and haunt your dreams. In this recent wave of sci-fi films, it's one of the best.Empire Online concludes, "Drawing on mythology and body horror, Annihilation is an intelligent film that asks big questions and refuses to provide easy answers. Sci-fi at its best." Rotten Tomatoes has a critics score of 87%.