'Riverdance: The Animated Adventure' is a baffling, terrible children's movie

After experiencing a loss in the family, an Irish boy named Keegan is whisked away by his friend Moya to the mythical world of the Megaloceros Giganteus. They teach him about the magic of Riverdance, and then Keegan helps save the fantastical place from the clutches of an evil pirate kind of guy voiced by Brendan Gleeson…