The movie falls into the “bad aliens invade Earth because they need a new home” category. Given the obviously advanced technology of this race, it’s questionable why they would resort to a ground assault on an out-of-the-way hick town in Australia (not to mention how they could transport millions across countless light years of space). Obviously, these aren’t things we’re supposed to think about. It’s not as if previous science fiction films haven’t been built on a similarly shaky foundation, but none of them were any good, either.
Alien invasion films are a dime a dozen but credible alien invasion films are few and far between. Occupation is one of the worst we’ve seen in a long time because the filmmakers are more concerned about visual razzle-dazzle and cinematic “moments” than a coherent story with flesh-and-blood characters. It’s the Hollywood mentality without the Hollywood skill.