Other mistake: When the two Americans are walking on the moors, their shadows are always in front of them, despite them having changed direction numerous times. Additionally, with the moon always being behind them, how are their faces being lit?
Other mistake: When Perseus wakes up in the stadium and he is talking to the old man, you can see a flesh coloured pair of shorts under his tunic.
Other mistake: When Arthur and all his knights assemble on hilltop at night and Merlin tells them all not to forget where the Round Table started, you can see the crew's spotlights reflected on the back of some of the knights' armour.
Other mistake: At the end after the barn fire, Marcia is at a tavern, ordering a rare steak. While it is believable that she escaped the barn fire, it is unbelievable that she is in the tavern wearing the same dress and necklace she wore prior to her transformation in the barn. All of her attire would have been rended in the transformation and lost in the fire. Unless her wardrobe consists of duplicates of the same clothing.
Other mistake: As Debbie walks through the foggy maze from her upstairs bedroom to the bathroom across the hall, she closes the door and then asks herself why she is in the kitchen, when the kitchen is obviously downstairs.