It's a found footage film about a party. The first twenty minutes show our heroes setting up the party. After that, the next hour or so is following the party, which starts at "insane" and keeps getting more apocalyptic until it's such a disaster zone that it's funny.
As far as I can tell, critics often hated it. It turned a good profit, though, and seems to have struck a particular chord with its chosen demographic. There were some real apeshit mega-parties that cited this film as an inspiration, which got so wild that there was at least one fatality. My DVD sleeve thus says "the events portrayed in this film are fictional" and that "no one should attempt to recreate or re-enact any of the scenes, stunts or general activities portrayed in the film." Most movies don't need to spell that out, even ones with extreme criminal behaviour, but this is not "most movies".
Did I like it, though? Hurm. That's a complicated question. For most of its running time, I wanted everyone to die and was hoping for a mass stabbing.
1. Thomas (the birthday boy) means well and makes sincere efforts to keep the havoc under control, since it's his parents' house. However those efforts are pathetic and underneath he also thinks the party's awesome. It's just that he's terrified.
2. Dax (the cameraman), who's the kind of person who'll hide in your cupboard and film you having sex. This is more characterisation than the cameraman usually gets in found footage films.
3. J.D. (the fat boy) isn't too bad, though. He goes along with everything and you'd have no problem with him going to prison, but it's not as if he's...
4. Costa (the waste of oxygen). Everything he says and does is vulgar. He'll show you a topless photo of "my girl back home in Queen's." (If that's true, she should dump him.) If a nice girl texts you, he might send back "I want your ass mommy" from your phone and then deny that he's done anything wrong. Later, if there's any chance of a relationship between you and her, he'll talk you out of it because he thinks it's all about having sex with people you don't know. (He says it slightly less bluntly, but that's where his brain's at.) He'll also take you to a drug dealer neighbourhood and then steal things for no reason from an unstable criminal whack job who might be ex-military. Costa's the one organising this party and he's full of promises about how everything's going to be okay and it'll be great.
In fairness, though, Costa has redeeming features. He's capable of apologising, although that didn't stop him from doing those things in the first place. He thinks it's going too far to burn down the house of a man with a wife and baby. Ummmm... I think that's it. His best feature, though, is that he gets punched in the testicles by a psycho dwarf. (He was funny.)
Anyway, I was talking about my reactions to the film. At first, I just thought Costa was repellent and that everyone was an idiot, i.e. a teenager. Once the party got going, I wanted to see them all machine-gunned. Eventually, though, events spiral so spectacularly out of control that it's funny. The hypocritical adults, the legal fallout, the utter lack of repentance from teenagers who've just trashed their own futures... although that said, the consequences could have been harsher. What happens is still basically nuclear-level bad, don't get me wrong. I even rather like the film's willingness to subvert the expected just deserts, but I definitely blinked at one of the multiple "get out of jail free" cards we see at the end.
Nonetheless, those last twenty minutes transformed my opinion of the film from "put it in the bin" to "that's actually quite cool". Now I like it. Getting that far was a bit of an endurance test, but I think its "what happened afterwards" gives the film a point.
The film's cool. It's also a parade of abhorrent mindlessness that might make you wonder if suicide bombers don't have a point after all, but that's one seriously extreme party. It's awesome. Some real-life party animals clearly thought so, anyway. It's like watching your friend jumping out of a third-storey window on to concrete. You can see it's going to end in screaming and broken bones, but at least it'll be a laugh. It's also worth pointing out that things like casual drug use are portrayed without judgement, but also with a clear-eyed view of how certain people start going downhill after they're taken. It has a swimming pool full of topless women. (If nudity is your thing, apparently the Extended Cut is the one to watch.) On the downside, though, it also has someone jumping off a roof holding a camcorder... and we don't see the footage!
If you watch this film, you'll probably think it's appalling. Personally I've talked myself into sort of respecting it, but I'm not saying you'd be wrong.