I was slightly worried when the story began with a saccharine introduction of perky twins in the idyllic English countryside, but the narratorial voice dropped out quickly and let the story tell itself, thank goodness. Sure, it's a sugar-sweet story, but by-and-large, that sweetness and charm worked with increasingly effectiveness as the plot developed. It took me a while to become absorbed in the story - I had my qualms about the first act. But by the second, I was sucked in, enjoyed more of the songs, and admired more of the magic of the story.
The first half of the musical didn't flow smoothly for me. There were odd transitions to sequences which intellectually made sense, but I didn't feel what I saw on stage was adequately conveying what I knew was happening in the plot. (The bamboo number especially. I also wished we'd been able to see the children reacting to the initial purchase of the car. Also, the Scumptious factory sequence struck me as oddly paced.) I missed hearing lines now and again, undermiked in the transition between scenes and numbers. The second act was notably better miked. Also, the chase sequence had its problems, and the moment when the car takes flight wasn't as magical as I'd hoped. Happily, the second time it flies was much more effective for me - it helped that there was crowd of people on stage blocking view of the flying infrastructure.
But there was plenty of good in the show as well. I loved the doll duet in the second act, the shiny, shiny car, the cascades of glitter from the ceiling, the childcatcher's vehicle, and the windmill set. The car flew beautifully the second time around, the Vulgarian duo were funny fairly frequently, and there were some good uses of the aisles among the audience. There were a few strong songs, and one very enthusiastic audience. The children in front of us knew the whole musical, hand gestures and all. When the actors came on stage for a bow, our neighbors got into a lovely flower-fight with the child actors near them on stage. We're guessing they're friends of the cast - or perhaps even ex-cast members.
I also liked all the visual references to other works. The toymaker's workshop reminded me of Gepetto's, from Pinocchio. The doll duet reminded me a great deal of the doll solo in Tales of Hoffmann. The windmill reminded me of Jenufa, but only because they're the only two musical theater pieces I've seen involving mills. The childcatcher was right out of panto-land.
It took several repetitions, but I finally find the theme song catchy. It's been bouncing around my head all day.