DeMonaco clearly hopes to make a significant moral statement on the level of Shirley Jackson's literary masterpiece The Lottery. Alas, his aim at political conservatives who support the gun lobby falls flat before he can pull the trigger.
That old horror-movie standard, a homestead besieged by psychos, gets remixed with a bit of Occupy-era class-conflict satire in the disappointing future-set thriller The Purge.
An effective balance of mood and style, not overburdened by grotesque displays of violence but suggestive enough to create a space of believable bleakness that warrants our continued interest until the very last frame.