As 'dark' takes on classic fairytales go, The Ugly Sisters has a lot going for it.

Cinderella's easy-to-hate step-sisters – Emerald (Abbi Greenland) and Pearl (Helen Goalen) – are recast as women more sinned against than sinning. Emotionally damaged, unsuited to life in the limelight and, well, ugly, they are victims of a PR smear campaign worthy of #TeamNigella.

The show is their intimate tell-all, delivered through song, physical sequences and narration. It is by and large a happy mix, though the physical theatre often overstays its welcome.

From their harsh, impoverished but happy life with single mum Ruby they are swept into a world of riches when she marries a banker type. But they are second-class citizens in their new life, while Arabella (Cinders, but with lashings of Mean Girls) monopolises the affections of Ruby and, indeed, everybody else.

They are accompanied by a noisy three-part band, who play the other characters when necessary. Prissy Arabella, guitarist Jonas Aaron doing a girl voice in a tiara, is particularly praise-worthy.

All three are led to compete for the heart of the prince in a reality TV show, a grotesque, inflated cross between The Bachelor and The X Factor.

The show's take-down of the tropes and excesses of reality TV is neat, if unoriginal. Behind the scenes the girls are egged on and plied with vodka, while outside a flood of sneering media coverage mounts.

Greenland and Goalen have their double-act down well; the sisters exude a compelling kind of anti-charm. Their attempts at humour inevitably fall flat, they require pep talks from each other in 'difficult' moments, and are much more scared of the audience than we of them.

An initially hilarious attempt by the girls to get glammed up, TOWIE-style, and win their mother's attention, becomes a sad emblem of their inability to fit in. Even I could tell Pearl had her skirt on backwards.

While the girls' story is effective, subtle it is not. The sisters aged 8 have essentially the same sociopathic innocence as they do when the narrative ends years later. And for such an energetic show, the lacklustre ending came as a surprise.

At 75 minutes, The Ugly Sisters is brief but not packed. Perhaps rightly, the sisters' picking over of how they were wronged before the world can feel self-indulgent, but it remains a story worth telling.