Shrek 2" is a paradox among sequels.

It falls short of the original in one key regard, yet rises above the original in another.

Relying even more heavily on catchy songs and pop culture references for humor, "Shrek 2" is not as funny as the first film. But the story is richer, more emotionally complex and better written.

In short, where the sequel tries to repeat the original, it fails, and where it tries to expand on the original, it succeeds.

"Shrek 2" opens with Shrek (again voiced by Mike Myers) on his honeymoon with Princess Fiona (Cameron Diaz), who became a full-time ogre at the end of the first movie. A montage set to Counting Crows' "Accidentally in Love," the honeymoon sequence spoofs "The Little Mermaid," "Spider-Man," "The Lord of the Rings" and "Austin Powers" in quick succession.

Throwing in a movie reference for the sake of throwing in a movie reference is a cheap, easy source of humor. This type of joke is genuinely funny only when unexpected (such as the "Little Caesar" reference in "Home on the Range").

But in the early going of "Shrek 2," all jokes are quick-hit pop references. During the first 20 minutes the characters barely speak dialogue that isn't borrowed from another movie.

"Shrek 2" improves as it slowly discovers its plot. Shrek and Fiona are summoned to meet her parents, the king and queen of Far Far Away (which is, of course, a fairyland version of Beverly Hills). Donkey (Eddie Murphy) tags along pretty much because that's what he did last time.

Things go badly in the magic kingdom after Fiona and Shrek arrive. Her parents (John Cleese and Julie Andrews) assumed Fiona was rescued from the castle in the first movie by Prince Charming (Rupert Everett) and that he broke her curse. Her father especially isn't thrilled to see her return as an ogre, with a husband bigger and greener than she is.

After a few predictable spats with his father-in-law, Shrek and Donkey set off on another quest.

They are joined by Puss in Boots (Antonio Banderas, who has a ball spoofing his Zorro image). Once the sword-wielding cat shows up, "Shrek 2" takes off, gaining a sure, satisfying feel for storytelling the first film lacked.

"Shrek" was wildly overpraised for mocking Disney, even though those jokes were facile. "Shrek 2" jabs more sharply at the tradition of Disney's fairy tale movies. Fiona's Fairy Godmother ("Absolutely Fabulous" star Jennifer Saunders) is the villain. Her ninny of a son, Prince Charming, is her henchman.

Fairy Godmother is a cross between the Godfather (get it?) and a Bel Aire plastic surgeon. As Shrek searches for a way to save his marriage, Fairy Godmother tells him, "Ogres don't live happily ever after."

Once again the main theme stresses inner virtue over surface beauty, but the script handles it with more satire. This Fairy Godmother's version of "Bibbity Bobbity Boo" celebrates consumerism and supermodel perfection.

When Fiona says she is happy with what she has, Fairy Godmother doesn't know how to respond. Nor does her enchanted chorus line. "Fine, be that way," grumbles the talking bookcase as it storms out the door.

While the computer animation remains well below Pixar's standards, PDI (DreamWorks' animation partner) has created lighting effects that make these characters appear as solid as the stop-motion figures in a Rankin/Bass Christmas special. The human beings still look stiff, but "Shrek 2" wisely keeps them off the screen as often as possible.

Occasionally even the blending of fairy tales and modern society is successful. In "Knights," a spoof of "COPS," the arresting officers use giant pepper grinders instead of pepper spray. The guests arriving at a royal ball get the same treatment as celebrities walking the red carpet at the Oscars – complete with commentary from a Joan Rivers who looks less plastic than the real thing.

So Joan Rivers was around in the Middle Ages; why am I not surprised?