Common Sense Note
Parents need to know that there is brief female nudity in a subplot about a helpful prostitute/single mother, though no sex results. She gets murdered for her troubles in helping out the hero, and there are several bloodied corpses plus fantasy violence in which zombie-like beings are decapitated or smashed. The nightmare imagery, recalling ghosts, vampires, and zombies (but with a sci-fi explanation) can be unnerving to sensitive viewers. A "director's cut" DVD lacks the opening narration that explains much of the complicated setup; some viewers might find this non-narrated version confusing.
Female nudity (topless and in profile) of a prostitute, bare-butt shot of the hero. Talk of an adulterous affair (which turns out not to have really happened).
Brief shots of bloody victims (female) of knife-killings, with spiral designs cut into flesh. Some of the zombie-like "strangers" get smashed/impaled, and one has the top of his head sheared off. Hypodermic needles plunged into foreheads.
In its weird way the film affirms the human spirit and individuality ("the soul"), compared to the super-powered but stagnant and dying alien race that holds people captive here. Even though the hero is set up to think he's a Ripper-like murderer, he really isn't, and even villainous-seeming characters are secretly working toward the liberation of humanity.
Drugs / Tobacco /
Some cigarette smoking, social drinking as backdrop.