If Wes Anderson had watched "Kill Bill" and then "John Wick" back to back and thought "I want to do something like that," the result probably wouldn't be very different from Gunpowder Milkshake.
It's a very stylish action romp with some pretty well known actors, focused on powerful female protagonists, and guns.
Like John Wick there are hints at a larger built-out world, interesting concepts and visual themes but, somehow with the stilted dialogue, shallow main plot, and random plot twists that excuse main characters from danger, responsibility, and lasting harm.
Don't ask too many questions, and enjoy the cinematography, and choreography where you can with this campy adventure.