Structurally, the writers combine the fairy tale form, the myth form and the buddy picture in a seamless whole. The community begins in trouble, which forces the hero to go on his journey. His goal is the opponent’s goal, to bring back the Princess. This allows the writers to save the big conflict with the main opposition for last.
On this strong line, the writers hang a series of anti-fairy tale elements for the hero and the audience to encounter. The story plays out the fairy tale structure, but also makes fun of it along the way.
By also adding the buddy picture element, the writers give the hero an ongoing opponent he can banter with along the route. That goes a long way to removing the episodic quality many myth-based stories have.
These great structural elements are also what make the fabulous texture of this film possible. By texture I mean details, sometimes comic, sometimes reverses of cartoon and fairy tale expectations. Texture is usually horizontal. That is, you are not moving the story forward, you are layering the moment. You are taking a pause in the forward line so you can please the audience with a little magic.
This film has the densest texture I’ve seen in a long time, and it’s why adults like this film possibly even more than children. Shrek is a film worth careful study.