Factual error: The movie is set in the Middle Ages. Therefore, the traders who come to the Winterland to sell their goods must be quite ahead of their time to carry fairly modern lighters. (00:04:20)
Revealing mistake: When the Polar Bear King comes to the Winterland castle for the second time the locals try to stop him. If you watch the encounter in slow motion you see that a) the bear's paws have the texture of a sturdy mat and b) the old guy who is being hit loses his balance in due anticipation. (00:23:20)
Factual error: People can't outrun polar bears. (00:23:45)
Revealing mistake: When the king's youngest daughter mounts the Polar Bear King the lack of effort reveals that she does this with the help of a cunningly placed stepladder. (00:25:35)
Plot hole: On arrival at the Summerland castle the Polar Bear King becomes human during the midnight hour (as part of the spell) and performs his husbandly duties with his carry-on wife. Why did he not become human during the journey from Winterland to Summerland which took several days? (00:32:40)
Audio problem: The fanfare player who announces the birth of the Polar Bear King's first daughter should have stuck to his instrument's overtones and not play a tune that requires trumpet valves. (00:36:40)
Revealing mistake: The crow that announces the happy news of his granddaughter's birth to the king of Winterland is doing most of its crowing without opening its beak. (00:38:30)
Revealing mistake: The king's youngest daughter is not supposed to see her beary husband's face while he is doing his midnightly human stints. Of course, she blows everything by watching her sleeping beau in candlelight and dropping wax on his forehead. Why is there so much light after the candle is blown out? (00:50:40)
Continuity mistake: On the way to the witch's castle the king's daughter falls into a river. She is totally drenched, but a moment later part of her hair is already dry again. (00:52:00)
Plot hole: The Polar Bear King (human version) is held hostage at the witch's castle. When the witch comes to pay him a visit in his cell she unlocks the door very elaborately. It is very surprising that the witch is not surprised at all that a) one of her subjects is inside the cell advising her captive on an escape plot and b) that this subject made it through the locked door. (01:03:40)
Continuity mistake: The king's youngest daughter climbs down a wall and drops a tightly sealed Erlenmeyer flask (invented centuries later) filled with a toxic potion. The flask is full when it is dropped, but partly empty after it has been caught and handed back to her by her spouse's earlier visitor. (01:08:40)