These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
A lot of the soundtrack could qualify, as could the sound-scape of the film in general, but special mention has to go to Jarvis Cocker's Running The World played over the end credits. The lyrics are a thing of beauty.
If you thought things had changed friend, you'd better think again. Bluntly put, in the fewest of words: Cunts are still running the world.
Darkness-Induced Audience Apathy: The problem some detractors have with the film. Most characters act completely reprehensible, anyone who does have a shred of likability is killed fairly quickly after they appear, and even the hero is dead by the end of the film. Though he is able to successfully evacuate Kee and her child to a save haven before his death, given the major Crapsack World setting any chance of it being a long-term recluse away from all the warring factions before it catches up to them is slim at best.
Everyone Is Jesus in Purgatory: Let's see, a young pregnant woman traveling to a far-off place with a "miracle baby", accompanied by a guy who isn't the father of her child yet still loyally sticks by her to see her there. Sounds like Mary and Joseph to me.
Gratuitous Special Effects: The childbirth scene. While this movie is sci-fi and usually averts this trope, a scene of a baby being born is usually filmed without the need of CGI.
Sci Fi Ghetto: Although the film is intended to be a thriller, banking on the chase with the set-up being necessary to justify the story, the sci-fi concept of a future with no children meant it should've fallen squarely in this trope. And yet, the critics loved it. Didn't quite make back its own budget in theatres, though, and several critics seemingly go out of their way to call it anything except science fiction (terms like "political thriller" were thrown around here and there).
Not to mention the fact that it was nominated for three Oscars: Editing, Cinematography and Adapted Screenplay.
Alas, no matter how serious the subject, the term "sci-fi" does still carry the lingering knee-jerk image of Buck Rogers-type Space Patrols and gee-whiz zap-pistols; such things were (fittingly) sparse or absent here.