James Fuji has posted some development storyboard artwork from the Astro Boy movie.
There's a sequence involving a giant robot (Peacekeeper?) uses Astro as a power source and attacking the floating city, and another featuring Zog and Astro's friends going inside the robot and trying to rescue him. Seems like this must be a different story element that was cut or changed from what finally got animated into the film.
Very cool to see this process!