Let's face it—Shrek the Third is a hit even before its release, with people flocking to it regardless of what critics will say. Is it beloved for its animation? The moral messages? Something to plop the kids in front of for 90 minutes? Probably all of those things to some extent, but I think it's the series' sense of humor that prevails. Above all, Shrek is a fractured-fairy-tale comedy that happens to be computer animated.

Shrek (voiced by Mike Myers) and Donkey (Eddie Murphy), back for Round 3

Fans of the first two will recognize this third installment as a reprise and reunion of their favorite characters. Shrek (voiced by Mike Meyers) and Fiona (Cameron Diaz) are happily married but enormously busy attending various royal events and media functions in the land of Far Far Away. They're filling in for Fiona's father King Harold (John Cleese), who is terribly ill and still a frog after the second movie. On his deathbed, the king names Shrek as his successor, but the ogre is reluctant to embrace royalty—and for that matter, parenthood, upon news from Fiona. He'd just as soon move back to the quiet swamp with his beloved and leave it at that.

Which leaves the task of recruiting the only other heir: the king's teenaged nephew Artie (Justin Timberlake)—short for Arthur, naturally. And so our hero sets sail, accompanied by his faithful companions Donkey (Eddie Murphy) and Puss in Boots (Antonio Banderas). If only things were so simple. A 90-pound weakling that even the nerds pick on, Artie lacks the confidence to become the next king. Shrek's grouchy, sarcastic remarks aren't likely to encourage him either.

Puss In Boots (Antonio Banderas) bids adieu to one of his feline admirers

Things are anything but quiet during Shrek's absence. Still sore after being cheated out of the throne in the previous movie, Prince Charming (Rupert Everett) decides to ditch his embarrassing dinner theater gig and plan a coup to take back what he believes to be rightfully his. To accomplish this, he recruits the legendary villains of fairy tales and children's literature—which can't be easy, considering that he foiled many of them himself, but he is charming after all. It isn't long before Fiona and the other princesses (Snow White, Sleeping Beauty, Cinderella) find themselves captives in their own castle, and it won't be clear which side has the upper hand until Shrek returns to confront Charming with Artie.

With Andrew Adamson now helming the Narnia movies, directing falls to co-writer Chris Miller (also the voice of Magic Mirror in the previous films), along with animator Raman Hui. Fans will rejoice that Shrek the Third is still close enough to the other two films to satisfy—Adamson still came up with the story and was executive producer. However, the series is beginning to wear thin for the first time.

It's certainly not lacking in the technical department. Watching the first Shrek recently, much of the animation hasn't aged well—CGI has come a long way in six years. But this movie often comes close to the quality of a Pixar release: fluid movement, realistic hair, and expressive faces.

It's royal primping for the new king

The voice cast is also strong, and not just because of the leads. They do well, but almost seem on autopilot for most of the movie—without giving away a key plot point/gag, there's a missed opportunity for Murphy and Banderas to really have fun with their parts. Timberlake impresses the most with unexpected comedic range as Artie slowly develops into a character. And Everett has fun with the arrogant, pitch-challenged Charming.

For sure, there are plenty of funny moments in this movie. I wouldn't dream of giving them away here, but Pinocchio and Gingerbread Man end up stealing the show again. There's also something strangely disconcerting about listening to kids giggle over a death scene with the sad expressions on characters' faces, but they obviously recognize that it's melodrama played for yuks.

And I was right there with them, laughing myself silly … for pretty much the first two-thirds, at least. The reason most people consider Shrek 2 the best of the bunch is because it's consistently funny throughout, using all forms of humor—self-referential gags for the fans, slapstick for the kids, subtle cultural jokes that only adults would get, and all three for grown-up kids like me. At some point in Shrek the Third, the humor becomes less frequent and more predictable, and I couldn't help but notice that the audience began to gradually laugh less as well. One suggestion: It takes more than off-key singing to make a parody of musical theater funny.

Artie (Justin Timberlake) and his former magic teacher Merlin (Eric Idle)

That ties to the movie's chief weakness. While the story is a natural direction to take the characters after Shrek 2, it's not as zany or unpredictable—more what you'd expect from a Nickelodeon cartoon than a multi-million dollar franchise. Yes, there are nice positive messages about taking responsibility, finding confidence, and ignoring the taunts of others. But they're delivered by tired conventions, not the creative storytelling you'd expect. The first two films surprised; this one merely goes through the motions.

In fact, the movie's greatest fault is the way it sets the stage for a big showdown between the good guys and bad guys in the third act, only to dissolve into some sappy moralizing with spats of humor and little action. This is followed by forced humor in the epilogue and animation in the end credits that are seem more like the cheap laughs of an Internet short (e.g. the Dancing Baby) than the Shrek we know and love. A surprising letdown after such a strong start.

Giving the benefit of the doubt because of the kids in the theater that clearly enjoyed it all, I'll readily admit the movie is fun. Just not at the same level of fun as the other two, which succeeded brilliantly because adults enjoyed them as much as children.Shrek the Third lacks some of the sharp wit that originally carried it, yet retains the sophomoric gags and adult humor that caused some parents to cringe with Shrek 2(see Family Corner below).