Hansel is diabetic as a result of his experience in the gingerbread house as a child. In the original script, Gretel was also supposed to have an eating disorder as a result the same trauma, but this was not included in the movie.
Was generally panned by mainstream critics, particularly for what they saw as its weak script and gratuitous violence. However, many horror genre critics were more positive, viewing the film as unpretentiously entertaining. The film topped the domestic box office on it's opening weekend and was a major hit in Brazil, Russia, Germany and Mexico. It's worldwide theatrical run gross exceed $200 million for the production cost of $50 million. Due to the commercial success of the film, which was planned as the first part of a series, Hansel & Gretel: Witch Hunters 2 (2016) went into development.
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.
When Ben is taking care of Gretel he brings her porridge and says that it's "not too hot, not too cold, but just right" thus making reference to Goldilocks and the Three Bears, another Tale from the Brothers Grimm.
In an interview with Famke Janssen at Cannes 2011, she stated that she took her role as the head witch because she had to pay off her mortgage. Janssen has stated multiple times that since 2007, she was prepping her writing/directorial debut Bringing Up Bobby (2011), where funding and distribution had gone through hard times, partly due to the 2008 economic crisis. She also had not done much acting in that period of time.
Adam McKay said in 2010: "The idea is, they've grown up and they hunt witches. It's a hybrid sort of old-timey feeling, yet there's pump-acting shotguns. Modern technology but in an old style. We heard it and we were just like, 'That's a freakin' franchise! You could make three out of those!".
The notices with images of the missing children and rewards being offered that are attached to milk bottles are a reference to the campaign started in the 1980s where pictures of missing kids were printed on milk cartons.