You can't see Michael Jackson's 94-minute movie, "Moonwalker," in theaters, but starting Jan. 10, you can buy the videocasette for $24.98. His publicists gushingly describe it as "a kaleideoscope of never-before-seen, extravagantly staged songs and dance numbers and breathtaking special effects (that tell) a moving story of friendship and confrontation between good and bad." Highlights of the movie: Sean Lennon in his acting debut, lots of animation, a montage of Jackson's 24 years as a performer and an extended treatment of the song "Smooth Criminal" in which Jackson takes on an evil drug purveyor by turning himself first into a robot and then a spaceship.