[This review contains plot details revealed in the first 10 minutes of Pixar's Up ] Pixar’s movies have always depicted fantastical worlds spun out of reams of boundless creativity. A rat who dreamed of becoming a chef, and who lived out that dream through controlling a guy by pulling on his hair. An epic battle between ants and grasshoppers. A city full of monsters, powered by the screams of children. A family of superheroes that try to defeat a spurned ex-devotee. It’s in the context of