The first half of FROZEN is pretty near perfect. It’s dark, soulful and bold, some of the best work Disney has ever produced. The film becomes more conventional as it goes on, but you can quite easily forgive any film that looks and sounds this beautiful.

A loose adaptation of Hans Christian Andersen’s The Snow Queen, Frozen follows two princesses whose happy childhood is brought to an abrupt end as the elder sister Elsa (Indina Menzel) manifests the extraordinary and deadly ability to conjure and control ice. She is shut away by her parents for the protection of herself, her subjects, and especially her carefree sister Anna (Kristen Bell) after a tragic accident caused by Elsa’s power. Elsa lives in isolation for years, much to the dismay of her sister, until one day she comes of age and inherits the throne, and hiding from the world is no longer an option.

In the hands of Kristen Bell and Idina Menzel, Anna and Elsa make for a captivating pair of leads, and their strained relationship is always the dramatic centre of the film. You see their love, fondness and unshakable friendship as the princesses play as children, then they are heartbreakingly torn apart for their own good. As Anna grows up she’s clumsy, energetic and awkward, but also cheerful and naively optimistic about her future. Elsa is the very picture of pained control on her coronation day, and during her long isolation has become insular and paranoid about the world, her powers and what will happen if they ever collide. Of course the inevitable happens and Elsa is outed in front of her subjects, and flees leaving an all-consuming winter in her wake. At this point, Menzel comes into her own as Elsa is finally allowed to be everything she can be, unleashing the full beautiful destructive power of her gift. Bell makes the perfect slightly ditzy innocent governed by her heart, and Menzel skillfully juggles the fear, the passion, the repression and the final glorious liberation of Elsa. You’re never left in doubt for a moment that, despite being animated, these are two real people, and you care about them and what they’re going through.

I wasn’t expecting there to be a horror genre influence in the latest Disney feature, but there certainly seems to be. I don’t know whether that was the filmmakers’ intention, but there’s definately something of the Universal Horror films about Frozen, with the persecution of an innocent monster by a angry mob of “Never-Europe” townspeople. That, and the fact that as her powers emerge as she becomes an adult, Elsa’s struggle is basically a frosty iteration of CARRIE (and that’s not a criticism).

You get some light-hearted elements as well, after all, what would a Disney movie be without cute sidekicks? You get two in Frozen, in the form of Olaf the daydreaming, good-natured snowman (Josh Gad) and Sven the dog-like reindeer who’s best friends with the main male protagonist Kristoff (Jonathan Groff). I don’t know what it is about modern Disney films and the presence of animals who aren’t dogs acting like dogs (also see: Maximus the horse in TANGLED). It’s certainly a weird idea, though it’s by no means unappealing convention.

Though a Disney film based on The Snow Queen has been on the cards for a while, it would have been impossible to realise even five years ago – that’s how much digital animation has advanced in a relatively short space of time. Much was made of the realistic movement given to hair and fabrics, and the sophistication of characters’ lip movements in Tangled (supposedly the first time you could conceivably lip-read an animated character was Rapunzel). Frozen improves on these groundbreaking effects further and has the added challenge of creating realistic snow and ice. Winter weather is difficult to execute in the virtual world, something so seemingly simple is deceptively complex in how it falls and how it can be manipulated by someone moving through it or if one of your main characters happens to be able to control it at will. The execution of the cold stuff is flawless and achingly beautiful, the current high-point of environment animation.

Apart from the annoying song sung by trolls, Frozen is probably the best outright musical Disney have produced since THE LION KING. The Oscar-winning “Let it Go” is stirring and powerful, the peak of the emotional crescendo that is Elsa’s character arc of liberation. The fragile, tender “Do You Want to Build a Snowman?” sung by Anna is really quite touching. I also loved the LES MIS-esque booming opening number “Frozen Heart” sung by ice cutters working the glacier, I just wish it went on a little longer, as it seems to end a little abruptly.

Again bringing up the trolls, which effectively function as this world’s bridge between fantasy and reality (as well as providing exposition and plot convenience) – they just don’t work. Not at all. They look, feel and sound like they’re in a completely different film, and their matchmaking song “Fixer Upper” is just awful. I have a few other gripes with the film, for instance Kristoff is a little bit too much like Tangled’s Flynn Ryder, except he’s obsessed with ice rather than money. There’s a late plot twist that is somewhat underwhelming too, and the film lacks a strong villain, though it doesn’t really need one with Elsa essentially functioning as the dual lead protagonist and antagonist.

Despite a few missteps and a retreat into convention after a brave first act, Frozen delivers great music, loads of heart and visual splendor. It’s certainly the best-looking digital animated feature Disney has made, and it has songs and vocal performances to match the studio’s highest points of the 1940s and early 1990s. What it also has is intelligence and maturity, and the two most complex, rounded and compelling female protagonists to feature in an animated Disney film. The days of the one-note Disney Princess are long gone, and they’ll hopefully stay that way if Disney keep working with such talented and perceptive filmmakers as Jennifer Lee and Chris Buck. SSP