A neon-coloured action flick that doesn’t pay homage to recent genre hits so much as openly ape them, Navot Papushado’s Gunpowder Milkshake takes a femme-centric approach to the uber-assassin format.

Playing Sam, a second-generation killer who followed in the footsteps of her absent mother Scarlet (Lena Headey), Karen Gillan projects an inhuman stoicism reminiscent of Nebula, the cyborg she plays in Marvel movies. This is a woman who returns from a shootout, sits in front of the TV with a bowl of cereal, and unflinchingly stitches up her wounds as if she were trimming a hangnail.

As her mom did before vanishing 15 years ago, Sam works for the Firm, a vague businessmen-gangster consortium that gives her assignments through oily Nathan (Paul Giamatti). But Nathan’s intel is imperfect, and the Firm holds her responsible for his errors: When they send her on a job where she unexpectedly has to kill the son of rival kingpin Jim McAlester (Ralph Ineson), Nathan and his bosses almost immediately start trying to throw Sam under the bus.

While Nathan tries to get Sam to come into the office and fall on her sword, another job gets her in a cuter kind of trouble: She mortally wounds a man who has stolen millions from the Firm, only to learn he was trying to save his eight-year-old daughter Emily (Chloe Coleman). Sam goes rogue to save Emily, who becomes her sidekick in ultraviolent mayhem, unaware that Sam killed her dad.

With co-writer Ehud Lavski, Papushado makes his biggest move in this direction when he introduces three “Librarians” whose books are just hiding places for various kinds of guns. Sam enters in search of reading material. Here, a Jane Austen volume conceals one kind of pistol, A Room of One’s Own hides another. But the conceit is far flimsier here, and the movie’s thin attempt to imply a backstory for the Librarians is so far from compelling it’s almost an embarrassment.

The Librarians enter the action wholeheartedly not long after Sam and Emily hunt down Scarlet, looking for refuge once a horde of McAlester’s suit-wearing thugs start hunting her. Scenes with Headey give Gillan some of her only chances to hint at human emotion, as Sam, the abandoned child, acknowledges she needs Mom’s strategic mind.

Had Gunpowder Milkshake devoted less energy to trying to look badass, it might’ve been something fun.