The slippery, multi-tentacled creatures seen in Gareth Edwards’ “Monsters” have adapted to Earth’s harshest environments, migrating from their Central American infected zone to other parts of the planet in “Monsters: Dark Continent.” Not so much a sequel as another stultifying character drama set in a world overrun by aliens, this 10-years-later spinoff switches directors and genres, as first-timer Tom Green (building on experience from British TV’s “Misfits” and “Blackout”) helms a taxingly over-earnest war movie set in an unspecified Middle Eastern country, where American soldiers deal with insurgents while the menacing MTRs (as they’re now called) lumber about in the background.

Though the human characters from “Monsters” are long gone and only a modified version of the creatures remain, Green’s film should benefit from brand recognition worldwide, sparking international sales and audience curiosity for a film that otherwise wouldn’t much interest moviegoers. Genre shingle Vertigo Films was clever in that respect, transforming the shoestring sci-fier that launched Edwards’ career (he graduated directly to “Godzilla”) into a franchise, while preserving the notion that any number of pics — not to mention novels, games and other properties — could be created in this world, where the concept of mankind awkwardly coexisting with this invading species provides the throughline.

That approach was both the novelty and the frustration of “Monsters,” in which the monsters themselves were almost incidental, providing atmospheric and visual garnish for a badly acted road movie, in which a photojournalist went deep into territory overrun by the squid-like aliens to extract an endangered young woman. Whereas that film focused more on the couple’s budding sexual tension than any tangible extraterrestrial threat, Green and co-writer Jay Basu hew closer to the formula seen in pics like “Independence Day” and “Battle: Los Angeles,” in which U.S. troops are sent to deal with the aliens, albeit indirectly.

The squad in question hails from economically depressed Detroit, where Michael Parkes (Sam Keeley) decides to enlist because, in his words, it’s better than dealing crack. Before shipping out to the godforsaken desert, Parkes goes on a hookers-and-booze bonding binge with gung-ho buddies Frankie Maguire (Joe Dempsie) and Shaun Williams (Parker Sawyers) — a repulsive display of tough-guy machismo that is swiftly undermined by the horrors of actual combat, in the face of which Parkes spends much of the film crying.

On the ground in who-knows-where (actually Jordan, but the movie inexplicably opts to remain unspecific), the men are berated into shape by Sgt. Noah Frater (Johnny Harris), one of those service-tour junkies, like Jeremy Renner’s character in “The Hurt Locker,” who can’t readjust to civilian life and therefore keeps saddling up to fight again. The mission itself has little to do with the aliens, as Frater’s team is being sent into hostile territory to extract four American soldiers — a setup that might have yielded a thrilling hybrid between “War of the Worlds” and “Saving Private Ryan,” if Green had anything approaching Spielberg’s storytelling instincts.

With the exception of an intriguing scene in which an eager crowd places bets on a dogfight between a pit bull and a smaller MTR, the humans seldom interact directly with these enormous E.T.s. Just imagine how dull “Jurassic Park” would be if the dinosaurs were seen exclusively in the far distance, as the paleontological safari intended, rather than endangering the characters in close proximity.

Who knows why Green chose to keep the alien encounters at such a far remove, other than to preserve the formula established by Edwards in “Monsters.” Though the sequel features far more footage of the giant beasts, including a spectacular nighttime scene in which one of the bioluminescent creatures ejects phosphorescent spores into the desert sky, the story remains stubbornly focused on relatively uninteresting human concerns.

While other military divisions bomb the bejesus out of the MTRs, Frater and his men are tasked with managing the Arab locals. These insurgents find the American presence as unwelcome as the alien one, setting IEDs and taking captives in a way that recalls contempo war movies (like “Lone Survivor”), whose style has clearly inspired the pic’s gritty, oversaturated aesthetic and deafening rock score (this on top of its already overkill Dolby Atmos sound design).

Subtract the MTRs and what remains is an intense, in-your-face study of desert combat dynamics, as Green concentrates his attention on how different personalities hold up under pressure. Harris, who plays Frater, is a cut above his co-stars in terms of depth and range, delving into the complex psychology of a battle-hardened officer. The trouble is that his mission simply isn’t very engaging, and one can’t help feeling that these soldiers are ignoring the 500-ton elephant in the room.

After 16 years on Earth, the aliens evidently aren’t going anywhere. In “Monsters,” these slimy cephalopods were mostly seen in or near water, and though not enough time has passed for them to evolve (at least, not in the Darwinian sense, where useful genetic mutations are passed along to their offspring), they appear to have adapted quite well to their new terrain. Designed by Christian Bull and convincingly brought to life by visual-effects whiz Seb Barker, the creatures look more Lovecraftian than ever and have even spawned other species, including a race of seemingly benign horse-like herds whose elimination would be as great a tragedy as the buffalo massacre — but that’s clearly a story for another “Monsters” movie.

Film Review: ‘Monsters: Dark Continent’

Reviewed at Sitges Film Festival, Oct. 11, 2014. (Also in London Film Festival.) Running time: <strong>119 MIN.</strong>

  • Production: (U.K.) A Vertigo Films (in U.K.) release presented with Solar Film Partners of a Vertigo Films production in association with 42. (International sales: Protagonist Pictures, London.) Produced by Alan Niblo, James Richardson, Rory Aitken, Ben Pugh. Executive producers, Gareth Edwards, Scoot McNairy.
  • Crew: Directed by Tom Green. Screenplay, Jay Basu, Green. Camera (color, widescreen), Christohper Ross; editor, Richard Graham; music, Neil Davidge; art director, Marwan Khair; sound (Dolby Atmos), Ian Maclagan; visual effects supervisor, Seb Barker; visual effects producer, Sara Rebuli; visual effects, the Post Republic U.K., Minimo; creature effects supervisor, Maurizio Giglioli; creature designer, Christian Bull; fight coordinator, Patrick Potochick; stunt coordinator, Jude Poyer; assistant director, Diana Cheklich; casting, Alexa Fogel.
  • With: Johnny Harris, Sam Keeley, Joe Dempsie, Kyle Soller, Nicholas Pinnock, Parker Sawyers. (English, Arabic dialogue)