Artistic License Physics: In the final act, hundreds of bags full of money are loaded onto a single barge with several people on board.
Nottingham's soldiers also wield riot shields and folding crossbows resembling guns against the Merry Men, who look like modern protesters with Molotov cocktails in glass bottles.
Artistic License History: Some of the outfits and props look rather advanced, like Robin's hoodie jacket and Nottingham's suit with lapels.
This seems incredibly unlikely as Nottingham is built upon sandstone.
Artistic License Geology: In mines located directly across the river from Nottingham, the locals seem to be mining and smelting iron.
Justified in-story, as John is trying to demonstrate that Robin's form of archery isn't nearly fast enough.
Arrow Catch: John is able to catch one of Robin's arrows at fairly close range with his staff.
Annoying Arrows: Robin gets hit by three arrows in the course of the film.
Anachronism Stew: Rather than approaching it with gritty realism à la the 2010 film, this adaption goes for a deliberately stylized approach to the Robin Hood myths, transplanting several modern concepts and designs in the setting, including rapid-fire ballistas, medieval vests made to resemble modern flak jackets, bandana-wearing and Molotov cocktail-throwing rebels, printed draft letters, etc.
This, and his jealousy over Marian and Robin's connection eventually leads him to pull a FaceHeel Turn and become the new Sheriff of Nottingham. His main reaction to Marian uncovering the Sheriff's dealings with the Arabians is to rant that she'll ruin everything for him.
Adaptational Villainy: Will Scarlet is portrayed much more negatively than prior incarnations, with his desire to make things better for the people of Nottingham being motivated by a desire to raise himself to the high classes through playing the political game rather than genuine concern.
Adaptational Badass: John is of average size in this telling, and to compensate his badassery is ratcheted up considerably.