The Lion, the Witch and the Wardrobe, Royal Lyceum Theatre, Edinburgh

Christmas has kicked off early in the Scottish capital’s theatreland, with traditional panto Snow White over at the King’s Theatre, and the Lyceum’s high-class offering – as befits the theatre’s 50th anniversary year – in the form of The Lion, the Witch and the Wardrobe.

Don’t count on any "he’s behind you" audience participation here, though – this is a far more traditional theatrical experience, a faithful adaptation of CS Lewis’s beloved children’s fable by Theresa Heskins, lovingly delivered in director Andrew Panton’s enthusiastic, energetic production – and warmly family-friendly, of course.

And faithfulness is, of course, a key idea in Lewis’s fantasy tale, and more importantly in the resolutely Christian values that inform it – alongside his mystical mix of English mythology, post-WW2 pride, ancient traditions and plenty more besides. Faithful is an apt description, too, of Panton’s approach to bringing to the stage the Christian message of Lewis’s children’s book, with the lion Aslan as a Christ-like Messiah sacrificed for the sins of the boy Edmund, only to return from the grave more powerful than ever. It’s a bit of a thorny issue for a 21st-century, and presumably largely secular, audience. But Panton strikes a nicely convincing balance between preachiness and disregard – there’s some vivid storytelling that remains true to Lewis’s religious symbolism, but it never feels over-emphatic.

It’s a bit of a show of two halves, though – vivid, dramatic and playfully theatrical before the interval, rather murkier when the story get more complicated and ambitious in the second half. There are some enchanting visual sequences early on, with racks of floating fur coats leading magically to the wintry wasteland of Narnia from inside designer Becky Minto’s wonderfully monumental wardrobe, suitcases transformed into train seats, and quickfire narration from the four youngsters stepping out of character to keep us all up to speed in Panton’s brisk pacing.

After the interval, however, it feels as though Panton’s theatrical inventiveness starts to falter in the face of Lewis’s more challenging scenes of war and sacrifice. There’s some simple but effective puppetry (from Edinburgh-based company Vision Mechanics) as the White Witch’s stone statues are brought back to life, but it’s brief and fleetingly used – the centaurs and eagles that Aslan summons for battle are disappointingly audio-only, for example. Aslan himself feels more symbol than fully filled-out character, despite an excited build-up to the great lion’s arrival led by the jolly beaver couple John Kielty and Gail Watson, resplendent in homespun knitted costumes (pictured above, with the quartet of children). Perhaps that’s intentional, but it nevertheless robs his harrowing sacrifice scene of its proper emotional impact (despite a couple of departures from upset younger audience members, admittedly).

Nonetheless, Ben Onwukwe makes a magnetic, dreadlocked lion, both menacing and affectionate, and the convincingly youthful quartet of children – Cristian Ortega, Claire-Marie Seddon, James Rottger and Charlotte Miranda Smith – are bright and down-to-earth, even if there’s not much of a sense of their transformation from timid wartime evacuees into confident Kings and Queens of this magical land. Pauline Knowles (pictured above, with Cristian Ortega) makes a suitably chilly White Witch, lisping and purring her way through her lines, and Ewan Donald multitasks nicely as fey faun Mr Tumnus (pictured below, with Claire-Marie Sneddon) and fearsome Maugrim, prowling wolf chief of the Witch’s secret police.

Young Scottish composer Claire McKenzie has a central role, too. Although the Lyceum’s Narnia adventure couldn’t be called a traditional musical, her score runs almost continually throughout, with dialogue sliding in and out of song. It’s got a distinctive, thoroughly beguiling Scottish folk twang, but it also feels like it’s missing a couple of big tunes – especially for the epic closing song with its pious refrain of "You can’t know, but you can believe" – and too much of the time it’s simply decorative rather than underlining dramatic tension.

All the same, it’s a confident, serious-minded production, thoroughly engrossing for youngsters and with enough theatrical flair to keep older audience members enthralled as well.

• The Lion, the Witch and the Wardrobe at Royal Lyceum Theatre, Edinburgh to January 3 2016