Everyone agrees this is a failure of a movie. Spoilers (if it were possible to spoil this movie any more than it already is) follow. As writers and filmmakers, what lessons can we learn?
Plot problems: The plot follows the formula “Hotshot FBI Agents come into town and bump heads with the local police while trying to solve a mysterious crime.” Hansel and Gretel are the FBI Agents — witch hunters — and appropriately, the antagonist, the village sheriff is identified early on in act one. Inappropriately, he is killed off about the middle of the film, but not by one of the heroes or anyone who has a good reason to kill him. My reaction was, “Huh?”
Another problem with the plot is inconsistency. When you set up a fantasy world, whether in Middle Earth or Tatooine, viewers will not object to the natural laws of your imaginary universe, even if how or why they function is not fully explained. What they will find upsetting is if you are not consistent in their application. In Hansel & Gretel the magic of evil witches “will not work against a white witch.” Except, inexplicably, and at the most critical moments, sometimes it does. “Huh?”, number two.
There are several other “huh?” moments as well.
Dialogue: When writing a period piece, a decision that needs to be made early is the patois - the variation of the language they speak. The English spoken in Gone with the Wind is not the same English spoken in Goodfellas. When you place your period piece in a foreign country, you also need to consider accents? An example of accents poorly done: In Highlander, a French speaker plays a Scotsman opposite a Scotsman playing a Spaniard. My ears!
There are basically two options. One, make your dialog sound “olde” with “thee’s and thou’s” or other dated words or phrases. The danger here is overdoing it and making the dialogue sound affected or silly. The second option, is to use contemporary English. This was done well in A Knight’s Tale. The way you can go wrong with the second option is to use slang or words associated with a time period inappropriate for your story.
In Hansel & Gretel someone chose the second option. The very first line we hear the grown up Gretel speak, as she points a gun at the head of the town sheriff is: “Let the woman go or I’ll blow your f***ing brains all over these hillbillies.” We’ll come back the the profanity in a moment, but “these hillbillies”? You are immediately taken out of the context of what appears to be an 18th Century German town. The town isn’t even in the hills.