Kinect Disneyland Adventures

Continue to follow the gold path in the park, completing tasks for the characters and this will unlock naturally.

Just keep completing the tasks assigned by characters throughout the park. (An exclamation point above the character indicates that the character has a task for you.) After completing 21 tasks, the achievement should unlock. The game doesn't have a screen that lists completed tasks that I'm aware of, but this should come naturally through game play.