The Internet buzz for District 9 has been so great that the film itself was always going to have a lot to live up to.

Part faux-documentary, part indie sci-fi, and populated by a cast of virtual unknowns, District 9 is the first film from writer/dir­ector Neill Blomkamp (with Peter Jackson on production duties). The basic premise is that 20 years ago, alien refugees came down to Earth and landed in South Africa. Unable to leave, the titular ‘District 9’ becomes their makeshift home on the edge of a disturbingly bleak Johannesburg. Neither the locals nor the government want them there, so the job of keeping them fenced in has been contracted out to a private firm, Multi-National United (MNU), whose interest lies more in exploiting the potential pay-ticket that their advanced alien weaponry has to offer.

With growing public unrest, the decision is made to relocate the 1.8 million aliens to a new trumped-up refugee camp, far outside the city limits. And as he’s married to the boss’s daughter, office geek Wilkus van der Merwe (Sharlto Copley) is appointed to head up the team.

Understandably, the aliens aren’t parti­cularly happy about all this. Inter-species tensions are high and the racial and xenophobic alleg­ories aren’t exactly hard to find.

Nicknamed ‘prawns’, the aliens are portrayed as a lazy, uninspired and feral species (with a bizarre penchant for cat food). And yet, the relationship between the cent­ral alien character and his son elicits more emotion and tenderness than anything the humans have to offer, and it’s not long before you find yourself rooting for the cosmic crustaceans.

Blomkamp made his name directing ads, including the Citroen ‘Transformers’ one from a few years ago, but thankfully his leap to the big screen is a world away from Michael Bay’s effort earlier this year. He tries to cover some very big issues in District 9, and succeeds for the most part without ever descending into greeting card schmaltz. And although the second half’s cat-and-mouse chase doesn’t live up to the more cerebral thrust of the first, it’s still an impressive debut.