Continuity mistake: A blond boy in a light brown shirt is attacked by a crow and goes from having no blood on his neck to having a lot of blood smeared on his neck between shots. (01:14:10)
Continuity mistake: When they arrive on the island of Talos, the bronze giant, Hercules and Hylus find the statues atop huge plinths. In close up, they are looking up at the statue of Talos, then in a wide shot they start to walk towards it across bare rocks, then in close up they are back where they were with plants behind them.
Continuity mistake: When Arthur is out hunting in the woods, Arthur is lying on a tree branch. In one shot, his pants leg is coloured brown, whereas, in the next shot, it is skin colour (as if he isn't wearing any pants). In the next shot, the brown pants leg has returned.
Continuity mistake: In the scene where the two men are carrying the coffin with the cross on it down to the crypt, the coffin is being held with the cross pointing towards the last man. But in the next shot the cross is pointing towards the first man, as the coffin has been turned around. Then in the next shot the coffin is in its original position, with the cross pointing towards the last man. There is not enough time for the coffin to rotate this many times between the two men carrying it.