Audio problem: When the band is singing "You're Out of this World," when one of the band members sings at one part, the music starts before he starts to move his mouth.
Factual error: Selena, the Goddess of the Moon, sets the next "earthset" as Zenon's deadline. One shot shows the Earth slowly sinking towards the lunar horizon while Zenon and Dasha watch. However, the moon takes exactly as long to rotate on its own axis as it does to orbit the Earth. As a result, the Earth does not rise and set as seen from any one location on the moon. It only rises and sets as you move across the surface of the moon.
Answer: There was a "find the hidden Zs" contest on the website for the movie. The Z on the microphone is part of the contest.