This sci-fi/action movie is clever, twisty, and sometimes shockingly violent. Upgrade is, as its name implies, a major step up for writer-director Leigh Whannell (Saw, Insidious). It's well thought-out and funny. It's imaginative. And it's a surprisingly effective mashup of several genres -- superhero (à la Unbreakable), sci-fi (in the neighborhood of The Matrix and Ex Machina), revenge (think Death Wish or The Crow), comedy (All of Me), and horror (more for the gore than anything else). Yet it manages to be its own thing; it takes direction from its influences without being derivative. It's a wild ride with good production values and great stunts.
The performances are also very good for the genre(s). Gilbertson, coming across as a mix of James Dean and David Bowie, is suitably freaky and suspicious as Eron. Simon Maiden's work as the voice of Stem, the implant, is deceptively skillful: The AI is programmed to recite words with a largely unchanging cadence, but Maiden squeezes quite a lot of mileage out of his lines. Gabriel is smart and sympathetic as the cop. But this is Marshall-Green's movie, and it demands a great deal of the actor. He plays an able-bodied person, then a quadriplegic, then a man who's consciously sending commands to a computer to move his body, and then a super-efficient, machine-like fighter and athlete. Like Steve Martin in All of Me, he manages to act while performing physical feats that surprise even him, including struggling against his own body. The emotional demands are also unusual for a genre film. Marshall-Green is up to expressing bliss, deep sorrow, rage, fear, and bewilderment -- all organically and all in context. Those elements, the visceral consequences of Grey's actions, and the extreme gore are more than enough to separate Upgrade from the sci-fi/superhero pack, but the movie is also quite well plotted. There are just enough twists to keep things interesting without straining credulity. For those who can stomach it, Upgrade may prove a pleasant surprise indeed.