The District 9 in the title is a trashy, garbage-filled South African shantytown/refugee camp for unhappy space lobsters marooned on Earth (they're called "prawns" in an obvious nod to South Africa's racist history). After 20 years, a multi-national corporation is contracted to relocate the shipwrecked aliens farther away from humans so that everyone (i.e. South Africans) will be happy. But there are sinister agendas afoot.
In a nutshell: really enjoyed it. Good premise, shitty plot but a decent, fun sci-fi movie overall. 3.5/5 dogs (a "B").
The rest of this post has spoilers. You have been warned.
District 9's heavy-handed apertheid/racism allegory worked better than I thought it would and there are some touches that really sell the setting. The arms dealers, black markets and general xenophobia and corruption all seemed realistic and awful. And the reference to muti killings--murders where body parts are cut out and used in folk magic--is really disturbing because that's something that would plausibly happen to aliens interned and isolated in fenced-in South African slums.
The story of this slum is initially presented as a documentary about stranded aliens awkwardly co-existing with humans. But early on, the fake documentary format is abandoned (without explanation) and District 9 becomes a dumb action movie with a stupid story. After an idiot bureacrat sprays himself with goo that starts slowly turning him into a crayfish (what is this, The Fly?), District 9 bumbles into rah-rah-action movieland. And a lot of bad guys die in satisfying ways.
In fact just about every human who gets mangled or disintegrated totally deserved it. Fun! But really not much different than Die Hard or something of that ilk, with likeable aliens instead of Bruce Willis.
(Actually, District 9 was a lot less gory than I'd heard. Then again, it was full of exploding heads, amputations and bloody disintegrations so I might just be desensitized. I dunno. I say it's not gory if the bad guy's exploding head makes you happy.)
Final word: It's a decent movie and I had a hellava great time watching it this afternoon. But it would've been a better film if it had a coherent plot (or even no plot).
District 9 invests a lot in its gritty, depressing, setting, but it betrays this realism with a dumb story and a cheap, hopeful conclusion. Then again, a better film would've been a lot less fun. In real life, the toxic combination of refugee camps, murderers, callous bureacrats, arms dealers and corporate malefeance doesn't lead to happy endings (sucks how that works). So I'll take District 9 just the way it is.
And I learned that cute, resourceful child heros aren't annoying when they have face tentacles. Who knew?