Someday, someone will make a post-Minority Report action movie that smartly comments on our relationship with technology. Upgrade is not that movie.

Grey (Logan Marshall-Green) is a stay-at-home mechanic. His wife Asha (Melanie Vallejo) works at a tech company. After dropping a repaired car off at the home of a reclusive billionaire, Grey and Asha are in a horrible accident. Grey is paralyzed from the neck down; conveniently, the reclusive billionaire reappears with an offer: install this computer chip in your spine and regain the use of your body. Of course, the computer chip has sentient thoughts of its own; more specifically, it encourages and enables Grey's thirst for revenge.

If that all sounds stupid, you're astute. It's dumb as hell. But it's also, somehow, less convoluted than it should be. It's a very thin layer of technology musings, resting atop a well-worn Death Wish-type story. Writer-director Leigh Whannell doesn't have much to say about tech, unless “implanting a mini-computer in yourself could prove problematic” is a pressing concern. Instead, he recognizes that it's a great excuse for a vague morality tale and some scenes where dudes get really beaten up.

The trailers sold Upgrade as a non-stop thrill ride, with Marshall-Green's character using computer-aided martial arts to smash his enemies. But in reality, it's a pretty slow burn. The violence can be pronounced and and visceral, but it's infrequent and Grey turns out to be far from a badass. He's pleased that the implant, known as STEM, saves his butt in a few sticky situations, but he's horrified by how easy killing becomes. He never signed up for newfound fighting abilities; he just wanted to walk again. That goes against the action movie grain, but you have to do more than just subvert the trope and then hit the showers.

The casting is occasionally inspired; 5'8” smarm machine Benedict Hardie would not be my first choice as an imposing bad guy, but his creepy demeanor more than makes up for his small stature. Alas, Betty Gabriel (of Get Out fame) doesn't have much to do as the detective investigating Grey's case, and Harrison Gilbertson couldn't be a more stereotypical creepy tech billionaire if he tried.

He does try, of course; everyone understands what kind of movie this is, and they give their all appropriately. But this is a Blumhouse production, and you (usually) don't see those for the actors or performances. You go for zany fun or big scares, and Upgrade offers a good deal of the former (with a little of the latter, mostly surprised gasps). Marshall-Green may be Tom Hardy Lite, but he deftly earns his paycheck as he shifts between a paraplegic, a man possessed by a robot, and a sudden killing machine. And he appears to be having a good time doing it.

It's just hard to feel anything stronger than casual enjoyment toward this movie. Whannell may make something out of nothing better than any filmmaker working today—his Saw franchise has grossed $453 million domestically—but there's very little depth to his work. Upgrade's ending is the most Saw-y part of the proceedings, and it's genuinely startling in the moment. But it also means very little and mostly serves to set up Upgrade 2.

If you're in the mood for mindless action and show up with low expectations, you may be impressed by what Upgrade turns out to be. But don't spend more than a few minutes pondering it afterwards, or it'll all fall apart like a cheap laptop.