Willy Wonka wows, but critics less impressed by Mendes musical LONDON (Reuters) - Director Sam Mendes earned grudging critical acclaim for a stage musical of "Charlie and the Chocolate Factory" but was always going to struggle in comparison to much-loved past productions of Roald Dahl's work. The glitzy new staging of Dahl's children's novel, which opened in London on Tuesday, battles universal acclaim for an earlier production of his "Matilda," Gene Wilder's whimsical Willy Wonka in the 1971 film and Johnny Depp's turn in 2005 - not to mention the audience's memories of the book. Acquiring the rights was a two-decade personal quest by the 47-year-old Mendes, best known for directing the hugely successful 2012 James Bond film "Skyfall" and winning a Best Director Oscar for "American Beauty." "I spent 25 years trying to get the rights for 'Charlie and the Chocolate Factory' to do on stage," Mendes told Reuters from the red carpet at the play's premiere on Tuesday. Critics praised Mendes for the sleek technical wizardry of the lavish show, which zips along in the second half using intricate sets, puppetry and ingenious costumes. However, Act One drags in its telling of how impoverished Charlie Bucket wins the golden ticket that will allow him to tour Wonka's chocolate factory alongside the greedy Augustus Gloop, gum-chewing Violet Beauregarde, spoiled brat Veruca Salt and the terrifying videogame addict Mike Teavee. Musically, critics had little time for the songs of Marc Shaiman and Scott Wittman. "Marc Shaiman's music is mainly unmemorable and the lyrics are hard to make out in the ensemble numbers," wrote Libby Purves in a three-star Times review on Wednesday. However, the eccentric chocolatier Willy Wonka - played by Douglas Hodge in electric green trousers, purple frock coat, spats and a top hat - won cheers for originality. "Douglas Hodge is a splendidly charismatic and disconcerting Willy Wonka, brilliantly combining jokes with a twitchy hint of the psycho," wrote the Telegraph's Charles Spencer in a three-star review. Critics also enjoyed the efforts of the child actors, with Jack Costello's performance as Charlie singled out. "Jack Costello's adorable portrayal of Charlie suffused the proceedings with a lovely sense of the boy's pining purity," wrote the Independent's Paul Taylor in a four-star review. The Guardian called Mark Thompson's sets, including Charlie's home and the brilliant chocolate room - complete with chocolate waterfall - a "sumptuous feast." Noted highlights were the special effects and costumes that allowed adults to play the diminutive Ooompah-Loompah factory workers, turned Veruca into a Blueberry and shrunk Mike Teavee. "On the positive side we can enter clever special effects (a good gag with a shrunken child) and a much better second half," wrote the Daily Mail's Quentin Letts in a three star review headlined: "Choc horror!" Most reviewers compared the Mendes production unfavorably with Tim Minchin's Tony award-winning musical version of Dahl's "Matilda" for the Royal Shakespeare Company which won a host of awards in 2012. But Financial Times reviewer Ian Shuttleworth gave Mendes four stars for creating warmth and beauty. It is flavorsome yet familiar, and above all it won't rot your teeth. Reporting by Paul Casciato, additional reporting by Rollo Ross; Editing by Raissa Kasolowsky