Artistic survival story
This is a memorable film, and well worth the time investment to watch with your older kids. I first saw it in a high school English class, but sought it out to watch with my son when he was a teenager.
The film powerfully communicates themes of optimism (not giving up), self-reliance, and our common fellowship with other people. It's not so much critical of "modern culture" as of the potential for dehumanization in urban life. We clearly see how impossible it is to be a cog in the machine when you're wandering the outback.
There is relatively little dialog; the film relies heavily on visual storytelling, and the cinematography is spectacular. This is a film to watch attentively and discuss - it's not a Friday night popcorn kind of film. Unless you take your Friday night films seriously.