SAN FRANCISCO -- Diverting and pleasurable to watch, "Stardust," a tongue-in-cheek sword-and-sorcerers romp bolstered by a top-flight cast, is most adroit when it plays the fantasy straight rather than sending up the genre. Adapting Neil Gaiman's novel, director Matthew Vaughn -- who wrote the script with Jane Goldman -- takes a sharp turn from his directorial debut, the slick neo-noir "Layer Cake," and displays a similar visual panache while working a completely different realm.

"Stardust" is less heavenly in its clumsy attempts at uproarious humor, which threaten at times to undercut the enchanting spell the filmmakers cast on the audience. A powerhouse cast, horses and swordplay laced with an abundance of whimsy plus romance should translate into decent boxoffice domestically and overseas.

This fairy tale opens in the mythical kingdom of Stormhold, where a star has fallen to Earth in the form of a young blond woman, Yvaine (Claire Danes), whose radiance, among other things, supplies magical powers sought by a motley crew of good and evil players. The dying King (Peter O'Toole, bellowing from his deathbed in his best stage voice) wants the star to secure the throne for his lame, useless sons.

In the parallel world of Wall, a village of mere mortals, Tristan (Charlie Cox) promises the elusive Victoria (Sienna Miller) that he will bring her a fallen star and sets out on a quest to find it. The ultra-evil, uber witch Lamia (the terrific Michelle Pfeiffer, who has gone from a delicious bitch goddess in "Hairspray" to a bona fide, wicked witch here), seeks the star's heart for its promise of eternal youth and beauty.

Only an actress as beautiful as the graceful Pfeiffer would allow herself to be rendered bald, aged and grotesque by startling special effects and makeup and have such a great time in the role. Her delight is palpable, and she gives a fully realized performance. Her Lamia is resourceful and genuinely scary rather than cartoonish.

Danes, an awkward, clunky film presence, is an odd choice for the naive, incandescent star. In a not-so-stellar performance, she overacts and struggles with an irritating British accent. Ricky Gervais is as roguish as ever, and Cox, making a convincing transition from fumbling boy to confident man, demonstrates a mastery of swashbuckling when it counts: a set-piece in which he vanquishes Lamia and her hideous sisters.

In a tedious sequence, Robert De Niro hams it up as pirate captain aboard an airborne "lightning" ship. The captain, macho in front of his crew, has a secret predilection for wearing petticoats and dancing the cancan in his private quarters. Straining for camp, his scenes are just plain embarrassing.

Shooting in the wilds of Iceland and Scotland, cinematographer Ben Davis conjures a land before time and, in tandem with Sammy Sheldon's battered costumes, Gavin Bocquet's production design is the right combination of fantasy and medieval grime.

Paramount Pictures
Paramount Pictures presents
in association with MARV Films a Matthew Vaughn/Lorenzo di Bonaventura production
Director: Matthew Vaughn
Screenwriters: Jane Goldman, Matthew Vaughn
Producers: Matthew Vaughn, Lorenzo di Bonaventura, Michael Dreyer, Neil Gaiman
Executive producers: David Womark, Kris Thykier, Peter Morton, Stephen Marks
Director of photography: Ben Davis
Production designer: Gavin Bocquet
Music: Ilan Eshkeri
Costume designer: Sammy Sheldon
Editor: Jon Harris
Yvaine: Claire Danes
Tristan: Charlie Cox
Victoria: Sienna Miller
Ferdy the Fence: Ricky Gervais
Primus: Jason Flemyng
Secundus: Rupert Everett
The King: Peter O'Toole
Lamia: Michelle Pfeiffer: Captain Shakespeare: Robert De Niro
Running time -- 128 minutes
MPAA rating: PG-13