Sharlto Copley's IMDB page suggests it's been a while since he's been in anything worth watching and so it was a third time around with this Copley / Neill Blomkamp classic. Four Oscar noms: picture, writing, editing, and surely it would have won for visual effects if it wasn't the year of Avatar.
Roger Ebert: three stars: space opera and not science fiction. A critic's pick by A. O. Scott at the time.