I very much enjoyed the whole being-torn-apart of the characters, dealing with inner demons while trying to do the "right" thing. And last but not least I endlessly enjoyed seeing how they overdrew so many clichés in this film - starting with one of the most hated phrases in the world (except for 'Murica) "God bless America", over spoiled and dumb teenage kids and finally Whoever missed that in conclusion the ONLY "good" human being (normal person, who is somewhat decent) was the one being chased/ killed? (not saying he WAS killed, not saying he WASN'T. No spoiler here! =) ) and all of the upper-class people where portrayed as lunatics (even psychopaths) missed the point of this film.
It's exaggerating and a bit quirky at times, but if you can enjoy this, you will love this film! Imagine a mix between "The Hunger games" and "Funny Games US" (nice coincidence with the "games") =) It's great! I really loved it. Go enjoy it! (And don't watch too much of the trailer... the first minute is perfectly enough, the rest might spoil it a bit for you!)