Big, Dominion Theatre review: Kimberley Walsh is a knockout in a zestful production with an uncynical spirit

Jay McGuiness and Kimberley Walsh in West End production of 'Big'
Jay McGuiness and Kimberley Walsh in West End production of 'Big'

Fans of the comic body-swap genre were certainly well catered for by the cinema of the Eighties. 18 Again! Vice Versa. Like Father, Like Son. All of Me. Feeling nostalgic? Neither am I.

Big, the 1988 hit with Tom Hanks, has honorary membership of this category. On the brink of his 13th birthday, Josh, our undersized New Jersey hero, gets an improvisatory test-run of the adult body to come when Zoltar, a mysterious, fairground slot-machine, grants him his wish to grow big. Josh becomes literally and figuratively the kid with the run of the (Manhattan) toy shop. If the movie couldn't disguise its creepiness-quotient in the Eighties, how will the material fare in this musical make-over by Richard Maltby and David Shire? It had a modest success on Broadway in 1996 and was reworked for the 2000 US regional tour. In Morgan Young's zestful production, the show hits London now in a climate that's more than ever aware of the vulnerability of minors to exploitation.

So the first thing to note about the musical version of Big is its uncynical spirit, which is wishful, sure, but refreshingly so. Obviously, the material would never leave the starting blocks if it had to move forward in the persistent shadow of alternative scenarios. From the early episode in the New York Port Authority Bus Station, this could have been the story of an atrocity waiting to happen. I never felt for an instant, though, that the music, lyrics or book (by John Weidman, who has often collaborated with Stephen Sondheim) are out to press upon us sunny sanitisation in the interests of giving a second tug on the udders of a cash cow. It helps a lot that the leads – Jay McGuiness (vocalist with the boy band The Wanted, and renowned graduate of Strictly) and Kimberley Walsh (of Girls Aloud fame and likewise a Strictly alumnus) have a lovely natural rapport as performers.

He's a delight as Big Josh. He manages to be very funny and truthful because he never overdoes the gangly goofiness. He projects unforced charm and he sings beautifully, with a range that easily encompasses the scared falsetto of the exiled boy-within pining for his mom (Wendi Peters) and the deeper reedy resonance of the nonplussed “adult” who finds himself with the keys of the car before he's even figured out what L plates signify. Walsh is knockout as Susan Lawrence, the toy company executive who first develops the hots for him and then a genuine renunciatory love. Her first number is a witty, blisteringly unsisterly song about her need to sack her female secretary. The latter, we gather, now spends all day in a trance of marriage preparation and experimenting with where to put the hyphens in her married name. Susan, by contrast, is both a bad girl and (almost despite herself) a good sport. Her eventual renunciation of Josh (after the often laugh-out-loud cross purposes) is all the more moving because of that.

The show has strengths in every department in the nifty way it shows innocence and experience infiltrating one another. It's a pleasure to say that one of the best performances comes from Jobe Hart, who is spot-on as Josh's loyal, assertive, sorely tried best childhood friend, Billy. Director Morgan Young supplies the exhilarating choreography. McGuiness and Matthew Kelly – who is very droll urbanely letting his silver hair down as the newly seditious owner of the company – do the honours with flair in the famous sequence where they leap with light-activating relish round a giant keyboard. The company Christmas Party, where the board members (virtually expressionist with angst) are forced to mingle with the kids, escalates into a heady, expertly flailing combination of the Charleston and the jive. David Shire's music has versatility and verve, from big band, to bluesy numbers, to one episode – a naughty scene in which we see how self-admiring and bogus is Susan's support group of moneyed Manhattan friends – which seems to be a direct nod to Sondheim's Company.

The handsome design allows for considerable fluency between Ian William Galloway's video images of russet suburbia and stylised big city perspectives that are projected onto the slatted glass screen within Simon Higglet's revolving design.

Theatre heightens the fantastic, fairy tale element in the proceedings, while by contrast the music takes you into unsuspected, liminal areas of feeling. I was surprised at how much my inner adult enjoyed itself.

To November 2; 0845 200 7982