Scott Renshaw’s review published on Letterboxd:
Writer/director Emerald Fennell teases with a concept that she doesn’t ultimately deliver—which isn’t inherently a problem, except that the concept she does deliver feels like it cheats on everything it’s supposed to be about. Carey Mulligan plays Cassie Thomas, once a medical student with the world at her feet—until a traumatic incident involving her best friend changed her life, and sent her on a single-minded quest for vengeance. Sort of. It’s not easy to articulate why this premise ultimately proves so frustrating, especially when Mulligan is so good at conveying the hard edges that Cassie has grown to protect herself. But what it comes down to is this: For a movie that poses at being an edgy apologia for vigilante justice, even as it acknowledges the psychic toll of holding onto anger over injustice, this thing ultimately seems to suggest that The System can work after all. Worse still, Promising Young Woman’s twisty-turny climax feels like a violation of Cassie’s fundamental personality. And worst of all, it doesn’t make a gotdam lick of sense if you think about it for more than half a second. A black comedy that also wants to be dead serious about the issues it raises, it’s a story that feels perpetually dedicated to pulling its punches.