The magic of Orange Wednesday let us see this film for £5.90 this afternoon at the Reading Vue. According to the Wikipedia article very little CGI was used: all the smashed, abandoned vistas were real examples of Americana.
At a superficial level this is the dark, wet, cold journey of the Father and the Son through a post-apocalyptic landscape as they seek some kind of dubious salvation at the coast. On the way they starve, repeatedly meet cannibal gangs which they escape by the skin of their teeth (!) and have sundry bad and unsatisfying encounters with drifters, thieves and the plain desperate.
View #1: it's all about the relationships
This is a story about a father and son pushed to the limit. Each deals with their desperate situation in his own way, but repeatedly the disillusioned Father finds himself learning from the more idealistic Son. I guess this is Clare's view: summary - the film is brilliant.
View #2: it's the ecology, stupid
Since everything non-human is dead, the intrinsic carrying-capacity of the land is zero. The only resources are detritus from previous civilisation like cans, and human beings (if you care to turn cannibal).
In this situation we're in classic cooperator vs. defector territory: the only way to survive is to be a defector-predator (like the cannibal gangs) or to join with other cooperators and build a new self-sustaining life-style.
The Father and the Son (more so) are "good guys", proto-cooperators. The film leaves it until the last few minutes to explore the dilemma of cooperator-identification and 'what happens next' in a cooperation strategy. ... Perhaps there'll be a sequel.
Unlike some of the reviews, I wouldn't call this a horror story: the fim is too intelligent to aim purely to shock. The audience didn't scream or groan at horrific scenes, they were content to absorb them as texture to the overall message. Verdict? Great film.