Young girls in party dresses filled the opening-night audience at the Walnut Street Theatre's Roald Dahl's Matilda the Musical: little Matildas, perhaps on the verge of discovering their own superpowers.

No doubt they had fun. Director Linda Goodrich's very broad and indisputably energetic take on this Tony- and Olivier Award-winning adaptation of the 1988 Roald Dahl children's novel is perfectly pitched to a family audience – high-spirited comedy largely shorn of menace.

The musical itself (book by Dennis Kelly, music and lyrics by the Australian comedian Tim Minchin) evokes the childhood nightmares and identity mysteries of Charles Dickens, the victimization and resilience of Annie, and the magical triumphs of the Harry Potter books.

Matilda's themes, while universal, also resonate with the age – particularly the show's glorification of (female) intellect and the power of storytelling. If only its own storytelling were a bit less convoluted: The first act speeds along, while the second meanders, piling on incident and coincidence.

The titular Matilda (a charming Jemma Bleu Greenbaum, who alternates with Ellie Biron) isn't an orphan, but she might as well be: Her parents, the Wormwoods, are both dim-witted and uncaring. Her dopey brother (Mark Donaldson) barely speaks.

Matilda's fraudster father (the elegantly buffoonish Christopher Sutton) can't even acknowledge she's a girl. And her mother (the terrific Lyn Philistine) is laser-focused on her dance moves with faux-Latin partner Rudolpho (the very funny Jacob Tischler). Their Latin number, "Loud," is one of the cleverest of Minchin's lyrics, enhanced by Michelle Gaudette's wonderfully comedic choreography.

Matilda is a 5-year-old genius who reads prolifically and holds the librarian, Mrs. Phelps (an over-the-top Demetria Joyce Bailey), in thrall with her fantastical stories. (Greenbaum struggles a bit with the British accent and her diction.)

School should be a great release. But this one, filled with terrorized uniformed children, is ruled by the vicious Miss Trunchbull, a stickler for (unfair) rules. Her motto is "Children are maggots," and her punishments include confinement in a cupboard filled with spikes.

Philadelphia favorite Ian Merrill Peakes, in costume designer Mary Folino's outrageous drag, plunges unreservedly into the role, squeezing out laughs with every inflection and pratfall. His first-act credo, "The Hammer," is slightly chilling and great fun.

Along with the librarian, Matilda finds an ally in a gentle teacher, Miss Honey (an endearing Laura Giknis), who turns out to have travails of her own. And instead of being bullied by her fellow students, as one might expect, Matilda — and her second-act telekinesis — eventually inspires them to revolt.

The children are hugely cute, but their ensemble numbers are sometimes muddy and hard to understand. Nicky Intrieri's persecuted Bruce is a standout; the kid's a star. (He will alternate with Akiva Schostak in the role.)

As usual at the Walnut, the production looks and sounds good. Robert Koharchik's set features stacks of books and blocks piled high, and Stuart Duke's rich, candy-colored lighting situates us in a fairy-tale world where the dangers and dramas of childhood can turn into happily ever after. Not soon enough for me.

Theater

Roald Dahl's Matilda the Musical

    • Through Jan. 6 on the Mainstage at the Walnut Street Theatre, 825 Walnut St. Tickets: $25-$97. Information: 215-574-3550, wwalnutstreettheatre.org.