This ain’t the Brothers Grimm, so forget everything you think you know about the fairy tale. 

Driven by their traumatic childhood experience, the titular siblings in “Hansel & Gretel: Witch Hunters” swap their breadcrumbs for the big guns as they seek to eliminate every wart-nosed wench in the land. But as the storied “blood moon” approaches, Hansel and Gretel must face a new evil that harbors a dark secret to their past.

Sounds pretty crazy, right? And the ads looked stupid, didn’t they? From the outside, this looks like another campy episode in the same vein of absurdity as last summer’s “Abraham Lincoln: Vampire Hunter.” There’s no denying that “Hansel & Gretel: Witch Hunters” is insane. We know it. The actors know it. And that’s what makes this bodacious bloodbath so much fun.

It’s by no means a “good” movie, but it’s not totally “bad” either. I had little to no expectations for “Hansel & Gretel.” I knew I wasn’t paying to see Oscar material, so I just buckled in and waited to see where the ride would take me.

What I got were crazy custom weapons, gnarly creatures and buckets of blood. I’ve seen these stunts before in movies like “Van Helsing” and the campier of last year’s “Lincoln” adaptations. It’s that same dark, loosely-“steampunk”-inspired horror story that attempts to put a fresh twist on familiarity. In the end, this is actually what makes “Hansel & Gretel” forgettable. 

But despite this gripe, I’ve got to hand it to stars Jeremy Renner (“The Hurt Locker,” “The Bourne Legacy”) and Gemma Arterton (“Clash of the Titans,” “Prince of Persia”). They both know how crazy the concept is, and it’s great to see them taking things lightly. The actors and the audience both know they’re just here for the popcorn, so it’s refreshing to feel like your stars might have the same feelings towards the movie as you do.

Because Lord knows with a title like “Hansel & Gretel: Witch Hunters,” nobody should be taking it seriously. The fun performances from Renner and Arterton, as well as Thomas Mann (“Project X”) keep the film from ultimately feeling like one too many of the witches’ sweets.

There are also a few fun twists that come towards the end. The villain (Famke Janssen) brings everything full-circle, and it ends up decently layered for January popcorn fare. Even though some may just call it beef jerky, I still enjoy a little meat with my junk food. 

I think “Hansel & Gretel: Witch Hunters” is well-cast with a humor-spiked script from writer/director Tommy Wirkola. The 3-D is decent for the fight scenes, but not totally necessary. I’d prefer to avoid being covered in wood chips and exploding body parts — if that’s okay.

All in all, I’d say this movie feels like a roller coaster that I’ve been on a hundred times. It’s a blast while it lasts (thanks to Renner, Arterton, and some nifty action sequences), but when it’s over I’m ready to move on to the next thing.