Joel Copling’s review published on Letterboxd:
In Upgrade, a man exacts vengeance upon the men who killed his wife. The crux of director Leigh Whannell's screenplay is as simple as that, and I mean this quite literally. Until one gets to the specifics of the plot, there is no deviation from this straightforward storytelling mechanism, at least until a twist of the knife in the final minutes attempts to rewrite some of our expectations. That twist comes right before a cut to credits that offers no hope for its main character, perhaps in an attempt to pave the way for future installments, something that, of course, is at the hands of its financial performance.
See my full review at Joel on Film.