Complex sentence: The third animated feature from Warner Feature Animation, Brad Bird's "The Iron Giant" (1999), performed greatly with test audiences but the studio decided to rush its release to the end of the summer with a rushed marketing push.
Split into simpler sentences: The third animated feature from Warner Feature Animation, Brad Bird's "The Iron Giant" (1999), performed greatly with test audiences. However, the studio decided to rush its release to the end of the summer with a rushed marketing push.