We've been here before . . .

Rating: 5/10 (18 August 2009)

I think it was trying to be Children of Men. with aliens. My complaints are too much graphic violence and too long. The aliens aren't very biologically plausible, either, but it's only a movie.
The plot's not really SciFi. It's more a comment on how humans treat large groups of refugees, minorities, and immigrants settled in their midst (I told you it was trying to be Children of Men). Similar ground (using aliens as a metaphor) was covered before, albeit differently, in Alien Nation. The story is set in South Africa, and the country's pre-Mandela history resonates throughout the film.
The most interesting thing in the movie is its lead, Sharlto Copley, whom I suspect will be the next big international actor everyone wants for their upcoming production. He turns in a helluva fine performance as a dorky stooge in the beginning, but a true hero in the end. If this movie's a big hit, everyone will be chasing him.
I don't want to be a plot spoiler so I won't elaborate on the story. Aliens or not, District 9 could be a refugee/minority detention camp anywhere on earth today.