Stephen Schwartz’s musical prequel has been brought to the big screen, with Erivo’s charismatic Elphaba exerting a planetary pull over a star-studded cast

As Kermit the Frog and the Hulk discovered: it’s not easy being green. Now another verdant character is gleefully brought to the screen by lyricist-producer Stephen Schwartz, screenwriters Winnie Holzman and Dana Fox, and director Jon M Chu in an adaptation of Schwartz’s Broadway musical, the first of two parts. It’s a sugar-rush fantasy with the overpowering star presence of Cynthia Erivo; it basically dunks you face-down in a hyperreal ball pit of M&Ms for two and three-quarter hours. I don’t have showtune-rapture in my DNA but this movie made a cleaner, sharper, cartoonier kind of sense to me than the stage show which I saw back in 2011.

This film is the prequel origin myth for Schwartz’s emerald supervillain-hero, stratospherically upping her status in retrospect: the green-faced Wicked Witch of the West from the 1939 movie classic The Wizard of Oz, based on L Frank Baum’s children’s tale. It was a character shriekingly played in the original by Margaret Hamilton, terrorising Judy Garland’s Dorothy, and now we are given a backstory for the pointy hat, the broom-transportation, the inky cloak (though shrouding the protagonist’s biological father in mystery). It pulls off the cheeky trick of making us interested in someone we know is destined for an ignominious death by water.