It's a pretty good flick but there are some major plot holes. The preppy rich kids are very weak. Sure the masks probably spook teens in the audience but anybody who's ever worn a mask knows they inhibit vision and are generally a pain in the ass to wear. Not good for hunting the most dangerous game I would think. Also when you are hunting a man and wife armed with heavy guns I don't think you're gonna do a bunch of ironic creepy crawl silly games. Kill mother fuckers then go kill more mother fuckers. Hey it's only one night a year.
Also on a serious note, Hollywood I spend a lot of money on your product. If you put out an R rated horror film, tits or GTFO. Not kidding.
It has a satisfying ending full of twists and turns. If you see every horror movie that comes out this year, see The Purge.