This is a psychological and possibly realistic apocalypse film. There is no massive action, guns blazing, weapons porn scene at the end. IRL we may not know what exactly is happening and this film captures that anxiety.
Check out the book, it's phenomenal. It balances the nuances of "something is happening" with the no information feeling of "maybe I'm overreacting?"
If you liked the Julia Styles film "It's a Disaster" you will love this.
