The film being categorised “horror” I thought this would be a spectacle, but “Annihilation” is more like “Arrival“. Something weird, unearthly, happens and men are going to investigate.
Somewhere in the USA a “shimmer” occurs which slowly grows larger. This “shimmer” looks like a rainbow waterfall. People who enter to investigate do not come back, until one soldier does. For a new approach it is thought to send a group of female scientists to see if they can find out the cause of the “shimmer” and perhaps even remove it.
The film has a nice, surrealistic atmosphere. The “shimmer” has some strange elements. Naturally some of these are scary, hence the “horror” tag, but these are bit small elements in the film. Similar to “Arrival”, things slowly become clear and the viewer is taken into the investigation and the past lives of the main characters.
Towards the end you get some nice, psychedelic and vague scenes. The end is a bit weak, but overall the film is quite nice.