Rotating stage sets, spectacular scenery drops, big musical numbers, appealing child actors and an adorable dog, the production of Mary Poppins by the Island Theatre Workshop has all the ingredients of an all-out family entertainment from the very beginning.

“There’s so much going on stage, even the young ones are mesmerized,” said Stephanie Burke, executive director of ITW’s children’s theatre program.

The show opened on Wednesday, July 25 at the Peforming Arts Center and continues through Sunday, July 29.

Played by soprano Rachel Enriquez, the acerbic and magical Mary literally drops into the lives of the Banks family, whose children are running wild.

“Mary flies,” said ITW artistic director Kevin Ryan, who is directing the award-winning musical. “We have a great rope team.”

She flies, sings and admonishes “spit-spot,” but this is not our parents’ Mary Poppins — the one so sweetly played by Julie Andrews in her Oscar-winning film debut for Walt Disney in 1964.

Author P.L. Travers famously hated the Disney film based on her Mary Poppins books, vowing never to let Americans spoon saccharine into her tales again. British theatrical producer Cameron Mackintosh was able to make some amends after Ms. Travers died in the 1990s, forging a deal with Disney that kept most of the original songs by Richard M. Sherman and Robert B. Sherman but permitted the action to hew more closely to her original stories.

With a book by Downton Abbey creator Julian Fellowes and nine additional songs by Britons Anthony Drewe and George Stiles — who also wrote new lyrics and arrangements for some of the Sherman brothers’ songs — the expanded, live Mary Poppins became a Broadway hit, playing more than 2,500 performances.

Still, “a lot of people don’t know this musical,” Mr. Ryan said. “There are so many things about this show that are so different.”

Ms. Travers’s Mary has a sharper edge than Disney’s, and the children Jane and Michael Banks, played here by Molly Crawford and Wyatt Thornton, are significantly brattier.

Winifred Banks (Shelley Brown) is not a suffragette, while George (Chris Beuhler) faces more complex challenges at the bank. The financiers are no longer the villains of the piece (Broadway musicals need bankers). Instead it’s Nanny Andrew, a fearsome figure of control who raised George Banks to be “an uptight mess in the midst of this dysfunctional family with no connection to his children,” Mr. Ryan said.

When Mary leaves the household, Winnifred brings Nanny Andrew in to restore order, with “Brimstone and Treacle” replacing “A Spoonful of Sugar” as the nursery theme song.

“She is a force to be reckoned with,” Mr. Ryan said.

However, he added, the ITW production won’t be quite as hard-hitting as the Broadway show, which saw parents heading for the exits with sobbing children in tow following more than one scene. For instance, the song Playing the Game, in which Mary tries to teach the children a lesson by bringing their mistreated toys to life, will get a different treatment through casting, costuming and make-up.

“On Broadway it was frightening,” said Mr. Ryan. The toys were played by adult actors in scary make-up, “right out of Stephen King.”

“I just couldn’t do that,” he said. “This is a family production.” So this week, some 15 local children are dancing and singing the roles of the playthings.

In a more pronounced departure from traditional casting, longtime ITW performer Jennifer Knight plays Bert, the friendly jack-of-all-trades who serves as a Cockney Greek chorus for the narrative.

“I am open to casting any way that makes the part work,” Mr. Ryan said.

Ranging in age from 8 to not far from 80, the ITW cast has been rehearsing Mary Poppins since May.

“They don’t know it yet, but they’re ready to go,” Mr. Ryan said on Tuesday. “It clicks.”

Mr. Ryan is abetted by assistant director Brad Austin, who also plays the role of the significantly-named businessman Von Hussler, and choreographer Ken Romero. Liz Villard is the lighting director.

The pit orchestra and singers are directed by pianist George Luton, a Vassar student who has been involved with ITW since childhood. “He parachuted in three weeks ago. Very much like Mary Poppins, he comes to save the day,” Mr. Ryan said with a chuckle.

With Mr. Luton are cellist Steve McGhee, clarinetist Ann Davey, flutist Julie Schilling and Augie Padua on horn. The youngest member of the pit ensemble, Mr. Padua has been a member of ITW’s children’s theatre program for five years and has played in its orchestra for three, Mr. Ryan said.

The part of Willoughby the dog, who holds a conversation with Mary on Cherry Tree Lane, is played by a castmember’s corgi named Jetty.

Remaining showtimes for Mary Poppins are July 26, 27, 28 and 29 at 7 p.m. with a 2 p.m. Sunday matinee. For tickets and more information, visit itwmv.org.