11/10/2013 11:24 BST | Updated 23/01/2014 18:58 GMT

Theatre Review: The Light Princess, National Theatre

It's finally here! After four years and even a postponement a couple of years ago, "the Tori Amos musical" has finally arrived at the National. For a show so long in the making, it has more flaws than you would expect but they cannot dim the magic of The Light Princess.

Princess Althea and Prince Digby are the heirs to the throne in two warring kingdoms - Lagobel and Sealand. Both lost their mothers early and are emotionally scarred as a result. Althea refuses to burden herself with an emotional connection to anything or anyone. As a result she floats, her feet never on the ground. Without a burden of responsibility or concern for anyone else, she is a free spirit forever in the air. Digby, on the other hand, carries the weight of the world on his shoulders. Depressed and sullen, he has not smiled since the day his mother died.

Though they've never met, both are instructed to fulfil their destiny and kill the other to claim victory in the war. Well, true love never doth run smooth, as they say...

Visually the production is an extraordinary achievement, with so many technical components coming together beautifully to realise this magical tale. The set design (Rae Smith) is fantastic. Whether it's the spiralling bookshelves of the ivory tower in which Althea is imprisoned, or the lavish life of the lake that lies hidden in the no-man's land between these two kingdoms, each is perfectly executed and add such texture to the scene.

The puppetry team behind War Horse (Finn Caldwell/Toby Olie) were drafted in to bring the animal kingdom to life. And whether it's the falcon, the frogs or the dogs of war, the results are perfect.

And at the centre of it all is the aerial effects (Paul Rubin) used to keep Althea afloat throughout the show. Through a combination of wires and a team of strong men (and women) how Althea is kept afloat is an achievement in itself.

Rosalie Craig gives a wonderful performance in the lead role. Her vocals stand out some way from her co-stars - and that's even when she's hanging upside-down. She also brings depth to her part, preventing Althea's feistiness from becoming a Disney-Pixar pastiche.

The production is not without its flaws though. Given the USP of this production as "the Tori Amos musical" it seems odd that the weak point is the score, but it is.

The show lacks that one big number, a show-stopper such as Over the Rainbow or, somewhat ironically, Defying Gravity. There's not a single stand-out tune.

Nor in fact is there much that's memorable about the score. The music was mid-tempo for most of the 2h 40min running time and the lack of variety in emotional and pace compounded the lack of unforgettable tunes. It was all a bit too much of the same.

However the lyrics are modern and ballsy, rather than whimsical - "you can stick your crown up your wazoo" Althea sings to her father as he wrestles with her to take her responsibilities as heir to the throne seriously.

This is a modern fairy-tale so the production goes out of its way to tick all the right boxes: a Uni education a greater achievement than being a princess - check; the gay couples - check; the drug references - check. All that was pulled off well and with wry humour but I found the comedic references to anorexia and force-feeding a little unsettling.

My main concern with the emphasis on the modern was that the tone of the show was so progressive and feminist that the love affair between Althea and Digby - the heart and soul of the show - was rather tepid. This is no grand passion, no Romeo and Juliet.

And given how this is packaged, with Althea as the modern heroine, (and this is a SPOILER ALERT!) it seemed odd that it is, in fact, Digby who saves the day and not the Light Princess.

For a musical that was four years in the making, its flaws are more obvious than perhaps they should be. However they do not outweigh its many positives. A West-End transfer beckons, for sure.

Lyttleton Theatre, National Theatre, London

To January 9, 2014