Factual error: The kitten in the Viking scene is long-haired. Long haired cats did not appear in Europe until many centuries later.
Revealing mistake: In the scene at the beginning of the film when the bus enters the village, you can see that the road signs are on the left side of the road (not facing the bus) and the continous line that separates the two ways is on the exit of the curve, not before the curve. This is because the action of the movie is set to happen in England but that scene was filmed in Romania, a country with right-hand traffic. (00:03:20)