Grey in red.

“Upgrade” is an offbeat futuristic techno-thriller in the tradition of B-movies about scientists tampering in God’s domain, made with enthusiasm (by “Saw” and “Insidious” creator Leigh Whannell) from the spare parts of other sci-fi stories. It has some clumsy dialogue and melodrama, but it also has enough tongue-in-cheek ingenuity and kinetic energy to compensate for it.

We are in the near future, with driverless cars on the road but not yet dominant, and with police work (at least the keeping-an-eye-on-everyone part) handled by drones. Grey Trace (played by Logan Marshall-Green — think Tom Hardy, then pull back a bit) is a grease monkey who loves his old-fashioned car almost as much as he loves his wife, Asha (Melanie Vallejo), who has an automated automobile and works for one of the tech companies that makes them. When a mishap puts them on the wrong side of town, Asha ends up dead and Grey ends up paralyzed.

Along comes Eron (Harrison Gilbertson), a blond kid who’s somehow the head of a competing tech company called Vessel who lives in an underground laboratory. He offers to implant Grey with “Stem,” a cockroach-sized widget and bio-mechanical artificial intelligence that will operate Grey’s limbs for him. Grey is pleased to be up and around again, if walking somewhat robotically, then surprised to learn that Stem (voiced by Simon Maiden) can talk to him. Stem is more observant than Grey is, in addition to being a computer that’s connected to all the other computers. Having Stem is like having Sherlock Holmes and the entire Internet in your head giving you advice.

Oh, and if you want to, you can grant Stem permission to take complete control of your motor functions and do your fighting for you — if, say, you happen to stumble across the scumbags who killed your wife.

Few things have delighted me more in 2018 than the sight of Logan Marshall-Green being astonished and appalled by what his fists, arms, and legs are doing to a hapless bad guy. Once that part of the story kicks in, it’s a loopy, frenetic race to the finish, with Grey keeping one step ahead of the detective (Betty Gabriel) working his wife’s case as he encounters underworld figures who have also had bio-mechanical upgrades (such as a gun implanted in one’s forearm). Grey’s relationship with Stem is amusing — it’s like if Michael Knight had K.I.T.T. in his head — and the movie, a combination of “Death Wish” and “RoboCop” (with the HAL scenes from “2001: A Space Odyssey” thrown in for good measure), is gleefully gory at times. There are some deeply nerdy sci-fi ideas at its core, if that’s your thing, but even as a simple genre exercise it’s a hoot.

P.S. I won’t tell you what it is so you can enjoy the novelty, but “Upgrade” does something with the opening credits that I’ve never seen before, even though it’s a simple variation that you’d think someone would have already tried. Bonus points for that nice surprise.

Crooked Marquee

B+ (1 hr., 35 min.; R, a lot of harsh profanity, a lot of strong violence and some gore.)