Based on the first book from Jeff VanderMeer's "Southern Reach Trilogy", "Annihilation" tells the story of a group of people who enter into a zone where the laws of nature have been warped. Think "Stalker" meets "Arrival" meets "The Descent" meets "Alien". Although it's a movie that asks some cool questions it could've been so much better in execution from a writing standpoint.
Although the main protagonist (played by Natalie Portman) has a sound enough reason to go into the zone (referred to as "The Shimmer"), the other characters portrayed by Jennifer Jason Leigh, Gina Rodriguez, Tessa Thompson, and Tuva Novotny feel artificial in their function in the story. Rather than following a group of complicated characters, we only get to follow one fully realized character while the others feel more like disposable bodies in a slasher film. These are supposedly some of the most intelligent people on Earth and they don't bother to wear hazmat suits when entering a place that's most likely radioactive. I'm reminded of how the characters in a movie like "Arrival" reacted to their situation. If you look at that movie, they clearly put an effort to protect themselves in a mysterious environment. Why couldn't they've done the same in this?
It's odd that the framing device the movie uses in the beginning tells us what went wrong and the rest of the movie shows us how things went wrong. It's a cool idea to jump back and forth in time but ultimately eliminates much if not all the suspense of the events that follow. Though, I sarcastically applaud the script for throwing in as much character development and exposition as possible into one scene. This is the moment when the movie should've noticed that maybe that weird interview framing device thing isn't working out. It didn't work for a dumb movie like "Atomic Blonde" and it certainly doesn't work for a high-brow philosophical science fiction film.
I love the way that the movie visualizes a place that is a refraction of nature as we know it. Locations often appear warped and prismatic. Creatures that have been affected by the shimmer are amazingly realized through a healthy mixture of CG, practical effects, and sound design. There's one scene in particular near the end of its second act- I don't wanna say too much about it but it's so damn cool. Oh man.
Annihilation starts off on a clumsy foundation due to its poor use of dramatic framing and clunky exposition, but it hits its stride during its second act onward and achieves a beautiful thesis that will be interpreted in a myriad of meaningful ways. This is how you pull off a great ending. It's such a shame that most of its dramatic impact had already been neutralized so early on. For similar premises done better, I would recommend the movies mentioned above as well as the anime "Made in Abyss" if you're into watching people enter a place that gives zero fucks whether you live or die.
P.S. As good as Natalie Portman and Jennifer Jason Leigh are in this movie, I wish their characters had been portrayed by non-white actors, despite the characters' ethnic ambiguity in VanderMeer's first book.