Alex Thompson’s review published on Letterboxd:
How unfortunate. This film takes a solid premise and a potentially drama filled scenario and punts on it. After a strong opening, maybe the best in a horror film since the Dawn of The Dead remake, the film settles us into a near-future in which unemployment is nearly eradicated and crime nonexistent except during the 12 hour period called The Purge when anybody can do anything and not get in any trouble for it. A fascinating idea, to be sure, and the film mostly fleshes out the idea well, albeit in a mostly clunky way full of radio and tv exposition. Even more interesting is Ethan Hawke's security salesman, a guy who sold his entire neighborhood their peace of mind and built a new addition on his house with it. If this seems like a too-good-to-be-true setup, that's because it is.
When masked people saunter up to the locked down house Ethan and his family are riding out the Purge in, I was prepared for an interesting twist which revealed that the masked assailants were the jealous neighbors. But that didn't happen. Instead we get people angry that Hawke's son has sheltered their prey, a homeless man they singled out for their bourgeois rage. This is dumb. Why wear masks if their violence is sanctioned? My hoped for outcome does come into play in some way later in the film but it's too little too late. Along the way the movie has squandered all the good will built by the premise through really dumb decisions made by the characters at every point and sub-par direction throughout. There is one great scene at the end which demonstrates just how great Lena Heady is as an actress and badass. But, along with the fantastic opening, these bookends do not make up for the horribleness in between.