It concerns a rather unlikely scenario in which the American government allows criminals to commit vile acts of violence and murder one night a year. This releases the inner animal in some people and purges the country of its bloodlust.
While the film pretends to examine to what lengths an ordinary man will go to protect his family, Prisoners, opening today as well, and Michael Haneke’s masterpiece Funny Games, make the definitive statement on violence and revenge.
The Purge, though not a bad film, doesn't treat the subject with the same honesty, frankness and horror. It turns into a commercial chase film, almost like a videogame, in which the audience roots for the good guys and turns into marauding slaughterers themselves as the culprits, with no real motivation except racism and bloodlust, cause havoc.
If you are in need of releasing your inner violent aggressor, this film might “cleanse” you of some violent feelings. But that's all it is: a violent video game.