Adapting a non-musical film for the stage is no easy feat. When it's a film with as firm a grasp on the nostalgia-addled hearts of a generation as Big – not to mention one that continues to enthrall younger viewers – it's doubly difficult. After all, there's a reason why the Tom Hanks-starring film remains a firm favourite amongst families, 28 years after he portrayed Josh Baskin, the 12-year-old in a rush to grow up. In a pre-Internet age, it placed an emphasis on two things: friendship and some good old-fashioned magic.

Any Christmas show at the Bord Gais Energy Theatre needs a hearty sprinkling of the latter, but BIG The Musical, originally staged in 1996, doesn't quite ping with the same vibrant energy as previous shows have. The pacing of the show is a major concern; the overlong first half is heavy with story, songs jammed into every available pause and a large ensemble cast that often makes the stage feel cluttered at times. There is a sense that Jon Wiedman's adaptation sticks a little too rigidly to the film's story, when perhaps paring it back to the essentials and building upon it the basics might have made for a more seamless production. At other points, key moments seem rushed: the scene where the young Josh encounters the infamous Voltar machine at the fairground feels like it's over before it's even begun, for example - arguably at the expense of another unnecessary song set in the company boardroom.

All that aside, there is much to like about BIG The Musical. In his first major theatre role, former boyband star and Strictly Come Dancing champion Jay McGuiness can sing and dance with gusto, and although his inexperience as an actor occasionally makes itself known, he nails the choreography and timing of the more energetic songs like 'Coffee, Black'. The walking piano scene – one of the most beloved from the film, which inspired a million visits to New York's FAO Schwarz toy store – is also handled with enthusiasm, affection, and some impressive footwork. Pop star, former X Factor alumnus and by now, experienced stage actress Diana Vickers plays the grown-up object of his affection, Susan, and although there is a palpable lack of chemistry between the two her voice is hugely impressive. There is some nifty staging, too - most notably in the transition between Big Josh and Little Josh.

If you take your seat expecting to be dazzled by effects or humming showtunes on your way out, you may well be disappointed. Otherwise, BIG The Musical is a decent family night out.

3/5