I can see this has garnered some pretty mixed reviews. I have to say that mine will be on the positive side after having finally seen it recently.
Doing what some of the better sci-fi in cinema history has done - take a trip down the lane called humanity and thematically reflecting quite consciously some of the issues to have affected South African history - and turns it into a visceral, violent and also entertaining sci-fi action film with brains and impact.
Mixing handheld camera/interview/security camera and regular style footage blended together as part of the storyline the film has a visceral-ness not often seen. The aliens themselves are not warm and cuddly to look at, they are not all nice. But neither are the humans..........as personified in the main character Wikus (Sharlto Copley) the human who finds himself on a journey from being a persecutor to being the persecuted.
That said, there are some gripes - the final third of the film does tend to slide into fairly generic shoot-em-up stuff that you will have seen before, the mechanics of the plot are fairly simple and straightforward and at times the effects are not always the best (that said, the film did not have a huge budget and did well with what it had). But then it doesn't entirely matter because by then if you're enjoying the film you will be completely involved with the characters.
Definitely an interesting film, and with rumours of a sequel I would be interested to see what the next part of the story is.