Writing a review for Ghost of Mars feels strangely like talking about a talented retarded kid. What the kid does is not entirely unimpressive, within the extremely narrow context of his own limitations, but any objective assessment of his achievement is going to come off as ruthless criticism.
In its own clunky, uneven, and embarrassing way, Ghost of Mars isn't utterly stupid. (See how awkward this for me?)
When reviewers can't think of an intro because the film has robbed them of the capacity of insight, they leap quickly into a plot summary, like so:
In the distant future, humans have begun to colonize Mars. They are terraforming (that is sci-fi geek speak for "creating a reason for the actors to not have to wear big old un-photogenic space suits") the planet and a series of title screens at the beginning of the flick reveal that Mars's atmosphere is very nearly like that of Earth. These title cards also inform the viewer that Mars is home to a matriarchal culture. This is the first of several odd creative flourishes that aren't totally wasted, but also never completely develop into a significant subplot. In fact, one of the most interesting, and simultaneously frustrating, things in this flick is the number of odd plot devices and narrative techniques it introduces only to fail to develop them in any real way.
Into this skiffy setting, we place a western plot. Specifically, a Howard Hawksian plot. Carpenter seems to have a real thing for Hawks. He remade The Thing, which legend has it was directed via proxy by Hawks. Carpenter's Assault on Precinct 13 lifts liberally from Hawks's classic Rio Bravo. And now we've got Ghosts of Mars which lifts from Hawks's El Dorado. Not that this is a bad thing. If you're picking influences, you could do a heck of a lot worse.
The flick starts with Nattie "Species" Henstridge at a discovery hearing. Nattie is the sole surviving member of a crew of Martian cops who traveled to a remote mining town to secure wanted outlaw Ice "Three Kings was a highpoint" Cube and bring him back to the capital for trial. At the hearing, she begins to describe what went down on her ill-fated mission. This will begin a series of flashbacks and narratives within narratives that, at first, strikes the viewer as an interesting way to tell what would otherwise be a straightforward action story. However, it quickly becomes clear that the leaping between perspectives doesn't change the essentially objective nature of the story. We don't get into conflicting viewpoints or get our expectations messed with. It is, like the gender politics that get introduced only to ever get lightly touched on, just another example of the flick's unfulfilled potential.
What unfolded was this: Nattie and crew – including the fortune teller's daughter from Carnivale, Pam "Coffy" Grier, Jason "Why am I famous at all" Statham, and some dude who dies first – find most of the town's citizens have become possessed by the spirits of the primitive and warlike pre-colonization Martians. These Martians spend most of their time inflicting themselves with piercings, listening to their leader rant in Martian, and killing humans. The cops, along with a trio of gang members who came to spring Mr. Cube and a handful of the town's survivors, must battle their way back to safety (except we know they don't 'cause the film reveals from the start that Nattie is the sole survivor).
What follows is, depending on your standards, fun general carnage or brainless explosions and lots of running around. The standard battle plot is given a slight tweak in that every time a baddie is dispatched the ghost inside them goes looking for a new host. Consequently, taking down a bad guy is in many ways worse than letting them live. That said, this too doesn't come too much (another wasted opportunity) as the solution the heroes come up with is to shoot the crap out of the possessed folks and simply hope for the best.
In fact, that seems to the prevailing ethos of the flick in general: just shoot a lot and hope for the best. And, that plan works about as good as can be expected. Which is to say, not all that well. Both the characters in the flick and Carpenter would have done well to come up with a plan B.