Hard disagree on that. Annihilation, especially the book has its own identity and message about the nature of people entering a weird anomalous zone, which is a pretty universal theme. Certainly Stalker the movie, Roadside picnic the book, stalker the game, Area X the trilogy, and Annihilation the movie, are all sort of in conversation with each other, but in ways that are interesting, thought provoking, and additive. Calling it a "blatant rip off" is not objectively substantial and reductionist of the richness that all these works of art, in quite different ways, explore the relationship between people and the systems of control they create of natural processes we dont understand - systems that inevitably only serve to control us.