Once upon a time, a brother and sister were left in the woods by their father.  They came upon a house made of candy that turned out to be owned by a witch, who used it to lure children and then fatten them up so she could eat them.  But the children outwitted the witch by shoving her in the oven.  The classic Grimm story is quickly dispatched in the first few moments of this fanboy fantasy so that we can get to the good stuff.  Hansel and Gretel, it seems, developed a taste for killing witches.  They grow up to be Jeremy Renner and Gemma Arterton, who haul their arsenal from town to town as something between bounty hunters, exorcists, and hitmen. And “Ghostbusters.”  It’s got special effects and some rocking fight scenes, and its cheeky anachronisms and brief running time (under 90 minutes) mean that it is over before the audience gets a chance to get tired of it.

There’s a lot of winking at each other and the audience.  A local fan of the duo (he has a 14th century scrapbook filled with their pre-Gutenberg news clippings) offers Gretel some porridge and assures her that it is not too hot or too cold but just right.  The local milkman delivers milk in bottles with drawings of missing children tied to them.  And the siblings have some Batman-worthy gear, including a device that draws electricity from a hand-crank, useful for zapping witches or, in a pinch, a bit of defibrillation.

Hansel and Gretel are hired by the mayor of a town where nearly a dozen children are missing.  The local sheriff (“Fargo’s” Peter Stormare) does not trust them and, more important, wants to stay in charge.  It does not help when Hansel tells the sheriff that the woman he is about to burn as a witch is not, and when Gretel head-butts him and breaks his nose.  He sends his own search party into the forest, but they are killed by a witch (Famke Janessen).  So, it is up to Hansel and Gretel after all, and it turns out that they have just three days before a “blood moon” will rise that gives the witches a rare chance to make themselves more powerful and much harder to kill.

The production design by Stephen Scott is imaginative and nicely varied, avoiding the trap of looking too Disney-fied.  The witches are eerily insect-like in their motions and sounds; there are moments when it feels like they are slightly more human-looking Predators.  Arterton and Renner look sensational in their tight, laced-up leather and handle the action scenes with a lot of verve.  It is silly, but it is entertaining.

Parents should know that the movie has intense and extensive fantasy violence with some graphic and disturbing images, including a medieval version of assault weapons, crossbows, knives, and a lot of throwing people around.  Human and witch characters are injured and killed.  Characters drink and use strong language and there is brief female rear nudity and a non-explicit sexual situation.

Family discussion:  Why didn’t Hansel want to talk about his parents?  Why did Gretel want to talk about them?  Why didn’t the sheriff trust them?

If you like this, try: “Stardust” and “Dragonslayer”