If you've seen The Happening then you basically already seen this one: a group of people trapped in a house with their blinds down. Nature is striking back and trying to kill them. There's the Black Guy (friendly, but eventually doomed), the Asian (innovative but too optimistic), the Old Lady (unreliable), the Old Man (grumpy but goodhearted) and so on. Haven't seen so many clichés in one movie for a long time. Not very scary, unless you find rattling leaves frightening.