Legend has it that the producers of Ridley Scott’s “Alien” pitched it to studios using just three words: “Jaws in space.” The producers of “Life” could have pitched their project using just one word: “Alien.”

Is that an unfair criticism? You be the judge: In “Life,” the crew members of the International Space Station bring an organism from Mars back to their lab. The thing grows fast, learns quickly and, unfortunately, turns out to be carnivorous. Lack of oxygen doesn’t faze it much, nor do electric prods or flamethrowers. After escaping into the walls of the space station, the creature begins picking off the astronauts one by one. The last survivor’s only hope may be to escape in a rescue shuttle.

That checks just about every box alongside the “Alien” screenplay, except for one thing: interesting characters. Instead, “Life” gives us the usual broad-brush personalities, including cocky technician Rory (Ryan Reynolds), sensitive guy David (Jake Gyllenhaal), icy microbiologist Miranda (Rebecca Ferguson) and paraplegic scientist Hugh (Ariyon Bakare).

Time that the movie could have spent making us care about these folks is instead devoted to a long windup in which the creature, Calvin, grows from adorable little microbe to man-eating monster. (To his credit, Calvin is a fairly imposing predator, a slippery, squid-like thing with an insect-like head.)

Without much to hang onto emotionally or thematically, “Life” becomes mostly about the logistics and mechanics of its plot. Here, too, “Life,” directed by Daniel Espinosa (“Safe House”), falls short. Characters run around banging on airlock doors and fumbling with handles, but it’s often tough to tell what exactly they’re trying to accomplish. Conversely, Calvin makes decisions based on information he couldn’t possibly have, unless he very quickly found the manuals for various satellite systems, engines and autopilot functions. It feels as if screenwriters Rhett Reese and Paul Wernick (“Deadpool”) came up with a list of required scenes first, then added explanations and justifications later.

Then again, maybe they just watched “Alien” and changed a few things here and there. It’s too bad there wasn’t a bit more creativity and intelligence to this “Life.”