Riz Ahmed's performance was the best thing about this movie. Hits the ground running, there were some pretty cool shots and the movie does a great job of building tension.
Apart from that, it was boring, the kids (particularly Bobby) was annoying and SPOILER ALERT there are no aliens. Turns out my guy is just suffering from PTSD, which we figure out pretty early. I don't mind subversion but when you push aliens for the majority of the movie, even having an opening that depicts parasites invading a host as well as showing proof of their existence via file folder it feels cheap. The execution could've be so much better. Plus after we figure out this weak M. Night twist are we supposed to route for the protagonist knowing that he's an unfit father?
Anyway, here's a brief plot summary to save you some time...After being dishonorably discharged, a vet serves a year in prison. He kidnaps his sons from the safety of their homes with mom and her husband and drives them cross-country, where he assaults and steals from innocent people under the false pretense that alien parasites are taking over humanity. He figures out that it's all in his head and presumably gets arrested.