For viewers enchanted by 2001's "Shrek" and 2004's "Shrek 2," "Shrek the Third" will prove to be more of the same. The jokes, a back-and-forth between broad bathroom humor for the kids and sharp offerings of satire and pop-cultural references for the adults, arrive at a clip rate. The incorporation of a cavalcade of fairy tale characters into the story is unsurprising but still enjoyable enough. The computer animation is colorful and visually pleasing. And at its core is a valuable, tried-and-true moral about the importance of embracing oneself and not being ashamed of who you are. This latter aspect is delivered in a decidedly preachy manner during a climactic speech, but at least the message is so blatant that it won't even go over the heads of younger audience members.

Now happily married but still unable to return to their swampy home, in-love ogres Shrek (voiced by Mike Myers) and Fiona (Cameron Diaz) have temporarily taken over the responsibilities as king and queen of the land of Far, Far Away when Fiona's father, King Harold (John Cleese), falls ill. Shrek knows he isn't cut out to be royalty, but he is suddenly looking at a lifetime of it when Harold passes away. The only other living heir to the throne happens to be the timid Arthur (Justin Timberlake), so Shrek, motormouth sidekick Donkey (Eddie Murphy), and the swashbuckling Puss in Boots (Antonio Banderas) set sail for the youth-centric village of Worcestershire to convince Arthur to accept the prestigious duty. Meanwhile, Prince Charming (Rupert Everett), still sore over Fiona's rebuking of him, sets out with a squad of outcast villains to take over Far, Far Away and its castle. No shrinking violets, it is up to the women—pregnant Fiona, mother Lillian (Julie Andrews), and baby shower guests Cinderella (Amy Sedaris), Snow White (Amy Poehler) and Sleeping Beauty (Cheri Oteri)—to put a stop to Prince Charming's evil plan.

If "Shrek the Third" is, indeed, so similar to the previous installments in the blockbuster series, then why is it also the weakest of the three? Because of exactly that reason—director Chris Miller (taking over for Andrew Adamson) introduces nothing to truly differentiate it from the others, and said formula is showing initial signs of aging. For a franchise set in a fractured fairy tale world, the possibilities are endless in dreaming up imaginative storylines and fresh places for the characters to go. Save for a brief trip to Worcestershire—a Medieval version of Laguna Beach—there are no truly new settings, the picture instead recycling gags about Far, Far Away's resemblance to Beverly Hills. The premise itself is fairly weak too, as is a theme—"be yourself"—that covers precisely the same ground as the earlier entries.

If the magic of "Shrek" and its lesser (but still very good) first sequel isn't quite as strong this time, "Shrek the Third" can still proudly attest to entertaining with its likable characters going through the motions and witty writing that pushes the limits of the PG rating. Unlikely though it may sound, the film features the funniest death-bed scene in memory, as King Harold, in the form of a frog, gasps his last breaths, and then regasps them again and again, as he utters his final rambling words. The animated facial expressions and comic timing of this sequence, as with most of the movie, are pitch-perfect. Also cute is the "Unhappy Hour" at the Poison Apple pub, where a wicked witch warbles on beside the piano, and a visit to the cottage of Merlin (Eric Idle), an elderly sorcerer missing a few of his marbles.

By this time, the voice work of the returning cast members—Mike Myers (2003's "The Cat in the Hat") as Shrek, Cameron Diaz (2006's "The Holiday") as Fiona, Eddie Murphy (2007's "Norbit") as Donkey, and Antonio Banderas (2006's "Take the Lead") as Puss in Boots—is comfortable but perfunctory. New talent includes Justin Timberlake (2007's "Alpha Dog"), appropriately awkward as the unsure-of-himself Arthur, and a quartet of funny ladies—Amy Sedaris (2006's "Strangers with Candy") as Cinderella, Amy Poehler (2007's "Blades of Glory") as Snow White, Cheri Oteri (2003's "Dumb and Dumberer: When Harry Met Lloyd") as Sleeping Beauty, and Maya Rudolph (2006's "A Prairie Home Companion") as Rapunzel—getting only a handful of lines each as they mostly make grunting noises while their characters kick butt.

After three features that, along with merchandising and tie-ins, have become a billion-dollar cash cow for Dreamworks, it is difficult to rile up the same sort of enthusiasm for "Shrek the Third." The films are clever, yes, but their oversaturated popularity has eclipsed their quality. With "Shrek the Third," the wheels of the enterprise have started to gradually creak. The big, green ogre and his ragtag pals are still an amiable lot to spend ninety minutes with, but a creative overhaul might be in the cards if the series is to continue to a part four.