Here is a lacklustre kids’ animation with an ostensibly starry voice cast including Ewan McGregor, Helena Bonham Carter, Mel Brooks and the late Terry Jones. (Oddly, David Walliams is announced and credited online as voicing the Guardian, while the film’s credits indicate the role is played by the prolific but little-known voice actor Stefan Ashton Frank. Wonder what happened there?)

However, it’s important to know before you watch that the lead characters who occupy most of the film’s runtime are two children not voiced by any of these luminaries. Young Elise and Alfie are twins who wish themselves into a magical world before getting into various scrapes. Sadly, Elise is deeply annoying and Alfie is a bit nondescript, which makes the whole thing rather a chore.

The involvement of Tim Rice as lyricist also promises more than it delivers. Hearing couplets like “Come on make a wish, do not be afraid of this,” you can’t help but feel like the venerable writer rifled through his old first drafts folder and reworked a bit of material that didn’t make the cut for his premium projects.

Sigh. Not to moan about how things were better in the good old days, things have clearly moved backwards in kid-aimed animation, so now we routinely get this sort of ersatz DreamWorks storyworld where everything looks like a screensaver and the dialogue is a blend of cod-Roald Dahlisms with a bit of pseudo-inspirational hugging and learning. McGregor as the Wish Collector does his best with material like “You don’t need wishes, you never did, you just needed each other”, but for parents and indeed discerning children, it’s pretty thin stuff.

• The Land of Sometimes is in UK cinemas from 20 March.