With all the fuss over Sleuth last week, it would be easy to overlook the fact that Kenneth Branagh has a another feature on release today. Indeed, the man once hailed as the finest actor of his generation is rapidly becoming known primarily for his work behind the camera. But The Magic Flute concludes a rather sorry trilogy of misfiring remakes that began earlier in the year with As You Like It. With a screenplay by Stephen Fry, this relocation of Mozart's 1791 opera to the Great War is the best of the bunch. But, unfortunately, this is rather faint praise.

Branagh opens brilliantly, with a long, fluid take accompanying the overture that tilts the camera down from a clear blue sky before traversing the No Man's Land separating the trenches and swooping back into the clouds with a squadron of bi-planes. However, for all its ingenuity, this sequence sets the tone for computer-generated images that will prove the picture's undoing by swamping the cast of newcomers playing out the story of Tamino (Joseph Kaiser) and his mission to rescue Pamina (Amy Carson) - the daughter of the Queen of the Night (Lyubov Petrova) - from the evil Sarastro (René Pape). Moreover, it betrays a clinical approach to novelty and spectacle that is too often devoid of magic.

The main problem lies with Branagh's self-conscious direction. Anyone making a musical is entitled to borrow from Busby Berkeley. But Branagh so over-uses the top shot (which looks down on the action from the eaves) that it becomes a stock tactic, lacking in value. His homages to Richard Attenborough's Oh! What a Lovely War (1969) are no more subtle or effective and, by the end, the camera placements have become so eccentric that it's difficult to concentrate on lyrics that are frustratingly indistinct for an English translation. Ingmar Bergman produced an admirable version of The Magic Flute in 1975 and opera fans would do well to track down a copy to expunge the memory of this charmless and disappointingly bombastic adaptation that fails to build on Branagh's astute musicalisation of Shakespeare's Love's Labours Lost (1999).

Having already tackled Sleuth, perhaps Branagh will be tempted to rework another old Joseph L.Mankiewicz project, like All About Eve (1950), which is reissued this week. There's certainly plenty of luvvie potential in its tale of an ambitious young actress (Anne Baxter) who trades on the vanity and insecurity of an ageing star (Bette Davis) in her bid for Broadway immortality.

Having seen his brother Herman win an Oscar for his screenplay for Citizen Kane (1941), Mankiewicz borrowed elements from its winning, flashbacking formula for this showbiz bitchfest, which seeks to understand what drives an aspiring starlet to clamber to the top over the corpse of her supposed idol. Yet Mankiewicz is nowhere near as dexterous a writer as his older sibling (with too many of his stinging bon mots sounding hand-crafted rather than raspingly spontaneous) nor as inventive a director as Orson Welles. Nevertheless, this remains a rousing and endlessly amusing melodrama whose merciless demythologising of the tawdry trappings of fame remains acutely relevant in these days of transient celebrity.

Moreover, the performances of its quartet of Oscar-nominated stars - Davis, Baxter, Celeste Holm and Thelma Ritter - are razor sharp. Returning to the screen after two years away and injecting each epigram with real venom, Davis turns in a magisterial display that seems founded upon the realisation that her own time in the spotlight was short.

An air of theatricality also pervades acclaimed screenwriter John August's directorial debut, The Nines, a triptych of interlocking vignettes that doesn't quite manage to pull off its audacious denouement. However, as so few Hollywood films are as willing to explore such serious themes with this degree of curiosity and intelligence, it's possible to forgive the shortcomings and admire both August's ambition and the commitment of leads Ryan Reynolds, Hope Davis and Melissa McCarthy. In The Prisoner, Reynolds essays a bad boy tele-actor who is placed under house arrest after torching his ex-girlfriend's belongings and is tempted into defying McCarthy's agency minder by Davis's mischievous neighbour. And the Beverly Hills mansion in which he is incarcerated also features in Reality, as Reynolds plays its owner, who agrees to be filmed for a TV reality show as he tries to greenlight a new series starring McCarthy for Davis's network.

But it's only in Knowing that the references to the number nine and the fleeting supernatural elements come together, as Reynolds's video game designer encounters Davis's hitcher after leaving wife McCarthy and mute daughter Elle Fanning at their broken-down car. The climactic metaphysical leap of both faith and logic falls a little short. But Kenneth Branagh would do well to note August's subtle camerawork and his restrained discussion of some pretty complex ideas.