From http://en.wikipedia.org/wiki/Cool_World

"During production, Bakshi's original screenplay was scrapped by producer Frank Mancuso Jr. and heavily rewritten by screenwriting duo Michael Grais and Mark Victor, best known for writing Poltergeist and Poltergeist II: The Other Side, and an uncredited Larry Gross. The film received mostly negative reviews from film critics, and was not a commercial success. Bakshi himself publicly attacked the film years after its release. He did not make another animated feature film until 13 years later, when he began production on the independent film Last Days of Coney Island."

It's kinda sad when you sneak a rewrite on a script written by the writer/director of Fritz the Cat and Wizards. Everything negative about Hollywood is true. Most of the people calling the shots don't know shit about what makes a good story.

I still enjoy the movie for it's blend of cartoon and reality, but Who Framed Roger Rabbit is far superior.