This is best described as the Australian Red Dawn (1984), which itself was remade in 2012, where a group off bored teenagers in a small Australian town go camping in the bush for a weekend and whilst they're away the country is invaded by a foreign power. The story follows their initial discovery of the invasion, their attempts to avoid capture and eventually becoming guerrilla fighters. It's a reasonably entertaining drama with a couple of decent set pieces including a big chase sequence although the whole thing is totally full of plot holes and at times daft. The inclusion of some romance that is more like a teenage high school drama slows the film down which lacks the action needed to make it really good. Apparently there were plans for sequels which were shelved when this failed to find an audience. Overall this is watchable but hinders possibly by budgetary restraints.
This was not so much a film, more of a pilot for a series. The plot did not really develop and ended unexpectedly. Still, the scenery was beautiful.