The home-invasion thriller is a horror trope we've seen done time and time again. It's practically the genre's bread and butter and for good reason; intrusion is an innate fear that we all have. This Adam Wingard film took what we thought we knew and twisted it into something foreign. What starts out as a by-the-numbers slasher flick fools you into a false sense of comfort, only to pull the rug out from under you.
Instead of an initially weak 'final girl' who grows into a reluctant hero, we get Erin, a trained survivalist who has no problem killing people. Instead of a group of highly capable, nigh unstoppable killers, we get a fallible group of morons who are unable to keep up with the protagonist. Instead of a deadly serious tone, we get Wingard inserting jokes and sight gags into uncomfortable scenes to make them even more uncomfortable.
The end result is a film that feels unpredictable, chock-full of unexpected twists and turns. By the time you reach the end, the film has even managed to incorporate a critique of the modern economy and class warfare.
Plus, if that's not your thing, it also has it's hero murder someone by stabbing a blender into his head and then turning it on. What more could you possibly ask for?