London. It's a newish festive tradition, but one that I'm willing to get behind based on last year's Paddington 2 and this year's long-awaited Mary Poppins Returns.

Nominated for 13 Oscars and winner of five, the original Mary Poppins was Walt Disney's crowning achievement. Julie Andrews' iconic performance and a standout soundtrack written by the Sherman brothers have delighted many generations of children. This sequel has big boots to fill.

The film picks up 20 years after the classic Mary Poppins left off. The original film's kids Jane and Michael have grown into Emily Mortimer and Ben Whishaw. Previously the scatterbrained son of a serious father, MIchael is now the scatterbrained father of two serious children (and a third, less serious child).

The Banks family home at 17 Cherry Tree Lane is about to repossessed and the recently widowed Michael could really use some help with the childcare (a timeless conundrum) so that he can keep his nemesis, the dreaded bank, from leaving his family destitute.

Enter Mary Poppins, floating in on a kite like she'd never been away.

Emily Blunt in the title role is playful but prim, perfectly under control, with not a move, a look, a gesture out of place -- all of which is extremely Mary Poppins of her. She is practically perfect in the way she captures Mary's specific brand of off-hand, unexpected warmth.

The sequel's new generation of children are all winningly charming and not at all precocious. Their palpable glee and amazement at Mary's antics is consistently infectious (although rivalled by that of Dick van Dyke, who is clearly utterly thrilled to be back).

The movie is ripe with enthralling subplots and oddball secondary characters played by the likes of van Dyke, Angela Lansbury, Colin Firth and a brilliantly disguised and totally eccentric Meryl Streep.

Lin-Manuel Miranda seems like he was born to play a cheeky, charming lamplighter with a twinkle in his eye. His character Jack is the sequel's Bert, and although we miss the little frisson between Andrews and van Dyke, we certainly don't miss van Dyke's infamous attempt at a Cockney accent.

Map the original and sequel side by side and you'll quickly see multiple parallels between plot points and musical numbers. The film reprises the mix of live action and animation that its predecessor was famous for, but to an even greater degree. At times it seems not only to pay homage to the original, but also to another Disney classic from the era, Bedknobs and Broomsticks, during an underwater bath time adventure.

For all its 2D effects, the film has a truly multi-dimensional quality to it that draws you layer by layer into its world. The sets are richly and generously adorned, and London is the London of fairy tales, thanks in part to art inspired by legendary Disney artist Peter Ellenshaw.

Due to the Golden Globe nominations preceding the film's release (the film receives mentions in a number of categories), we can presuppose that the Academy may once again look favourably upon Disney's magical nanny narrative.

Surprisingly, the film's weakest point, and the area in which it fails to live up to its legacy, is its musical numbers.

The film goes off-kilter during a performance of "The Cover is Not a Book", during which Blunt is recast as a bob-haired flapper and Mary Poppins all but disappears. The song features a Hamilton-esque rap in the middle -- a nod no doubt to Lin-Manuel Miranda's self-penned hit musical. But does it fit here? I fear not.

It's curious that after the success of Hamilton and the Moana soundtrack, which Miranda also wrote, that he wasn't roped in to write the songs for Mary Poppins himself. (He is on the hook to do the music for Disney's planned live-action remake of The Little Mermaid, however.) It's not as though Grammy, Emmy and Tony award-winning composer Marc Shaiman, who did write the score, doesn't have the credentials for the job, but the music falls a little flat on the whole.

There are some songs that could have staying power. "Trip a Little Light Fantastic" (a companion piece to Chim-Chiminee), has the most potential, followed by the lullaby "The Place Where The Lost Things Go". But could they become beloved Disney classics?

Even the minor songs from the original Mary Poppins film are stuck firm to my memory. Twenty years on, I'm wordperfect on Sister Suffragette and can't take a step past St Paul's Cathedral without the minor chords from "Feed the Birds" reverberating around my head.

But then nostalgia can be a kind of poison at times. And just as Mary Poppins is passed down in this film to a new generation of Banks siblings, the decision ultimately lies not with adults, but with the children of 2018 and beyond.

Will they, in 20 years time, get goosebumps when they hear snatches of songs? Feel shivers down their spine when they see the silhouette of Mary Poppins appear on the London skyline? It's hard to imagine this sparkling adventure with all of its earnest enthusiasm and magical mayhem not leaving an imprint on impressionable minds, and I'd hazard a guess that their own childhood memories will be all the richer for it.