Thanks to Lurple's review, I have sought out and watched this rape revenge flick by Ngai Kai Lam, who also directed The Story of Rikki and The Seventh Curse, both prime examples of over the top Hong Kong film-making.
After those films, I would have expected more than a little bit of extreme violence, but would not have expected the intensity of acting and characterization the film delivers. This is of course thanks to the excellent performances by Pauline Wong and Chin-Ying Lam (known from a multitude of Shaw Brothers films, Mr. Vampire and so on, and so on).
The violence starts out gritty and quite nasty, only the finale when our avengers turn into psychopathic variations on MacGyver shows something of the exuberance of the violence in Rikki (which would be completely out of place in a film like Her Vengeance), but toned down to a more down to earth feeling.
Especially good, and showing off Ngai Kai Lam's quality as a director, is the intensity the movie reaches through reduction. There is no filler in the film, every moment is a necessary escalation on the way to its conclusion.