The good stuff
Though he's a vampire, hero Edward Dalton is actually a fairly positive role model, working tirelessly on a blood substitute to sustain his brethren (and refusing to drink human blood himself, believing that he shouldn't relieve his own suffering when so many others suffer). When a better solution arises, Dalton risks his life for it. When the time comes for him to work with humans, the groups put aside their differences and learn to trust one another. Although Dalton's brother joins an evil vampire army to hunt humans, Dalton honors his family ties.
What to watch out for
While the movie doesn't have strongly positive take-aways, its story is a metaphor for humans depleting natural resources with no concern for the future. The bad guys are shown trying to earn a profit from this crisis, while the heroes continually fight for the betterment of mankind and vampirekind. Human and vampire enemies must learn to trust one another.
Tons of fantasy violence -- it's less a horror movie than an action movie filled with fighting, gore, and some disturbing imagery (i.e. humans hanging from machines that harvest blood). The heroes wield crossbows and knives, while the bad guys generally fire high-powered dart guns (also a Taser). There Gallons of blood are shed, including guts spattering on walls, beheadings, limb-tearing, and an exploding head. In one subplot, starving vampires who are deprived of human blood begin to mutate; viewers see disturbing photos of this process.
The heroine runs around braless and in a tank top. But the story's vampire troubles leave very little time for sex, kissing, or romance.
Several uses of "f--k"" (including "motherf--ker") and plenty of uses of "s--t." Also words/phrases like "da--it," "hurts like h--l," "godd--n," and "life's a bi-ch and then you don't die." One character uses colorful euphemisms like "it's as safe as barebacking a $5 whore."
Not an issue.
Drinking, drugs, & smoking:
Characters smoke a lot of cigarettes.