When Hansel and Gretel first arrive at the candy witch's lair as children, Gretel pulls off the end of one of the icing icicles to eat it. In the next few shots, the icicle is shown as intact when it should have a blunted end.
At the beginning of the movie when Hansel and Gretel are fighting the witch in the woods Hansel grabs the witch and slams her down on a log behind him. When the witch starts to back away from Hansel the log is in two parts with about 2 to 3 feet between pieces. In the very next shot the log pieces are almost touching with a thin gap. As Gretel locks the witch in place in the air the log is back to a wide gap of 2 to 3 feet.
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.
In the opening scene, the father is silhouetted against a curtain while holding a lamp. The glowing lamp is part of his shadow.
The article texts of the "newspaper articles" in the opening credits have nothing to do with the article titles; two different newspapers have the same text.
"Hansel" and "Gretel" are diminutive forms of "Hans" and "Greta" respectively. They are names that children use. As the children grew up, they would change to "Hans" and "Greta".
The pool of healing waters Mina & Hansel get into obviously has a man made edge with the water lapping over it as they move.
Hansel and Gratel should be twins, but Jeremy Renner (portraying adult Hansel) is 15 years older than Gemma Arterton (who plays Gretel).