Tommy Wirkola got the idea to create the film based on the adult lives of Hansel & Gretel in 2007 while at film school in Australia. After being discovered by Gary Sanchez Productions, Wirkola pitched the idea at a meeting with Paramount Pictures and won a contract.
The movie's cast featured two former Bond Girls: Famke Janssen from GoldenEye (1995) and Gemma Arterton from Quantum of Solace (2008) made and released around thirteen years apart in the James Bond film franchise. Both had Ian Fleming-esque "Pussy Galore"/"Mary Goodnight"-like double entendre character names, which were "Xenia Onatopp" and "Strawberry Fields" respectively.
Originally scheduled for release in March 2012, was delayed for ten months to accommodate Jeremy Renner's appearances in The Avengers (2012) and The Bourne Legacy (2012) and to give Tommy Wirkola time to shoot a post-credits scene.
When Hansel and Gretel are in front of the candy house, he eats colorful candy and she eats the white icicle. However when they go inside both of their mouths are colored.
When Mina is tending to Hansel's wounds next to the lake his arm changes positions between shots - from resting on his knee, then his thigh, then his knee again.
It was to match Jeremy Renner, as it would be weird for siblings to have different accents.
Q
What are the differences between the Theatrical Version and the Unrated Extended Cut?
A
This Unrated Extended Cut of the movie is a really satisfying affair. Even though it adds over 9 minutes of material, barely anything of that is useless. Much of the new stuff is so entertaining that it bares the question why it wasn't included in the short theatrical version in the first place. Especially striking is that the Unrated has considerable additions in the violence department. It wasn't even necessary to put the ominous "baby scene" back in to heighten the death toll. Wirkola stated in an interview that this moment provoked shocked reactions in test audiences and was removed. All in all, the film's fun factor is visibly increased by the Unrated Cut, making it decidedly recommendable for viewers that already had fun with the theatrical version. A detailed comparison between both versions with pictures can be found here.