IF you're looking for the Scottish theatre festival with the most impressive combination of artistic innovation and quality of performance, there's a strong case for arguing that you'll find it in Edinburgh's programme of international theatre for children, the Bank of Scotland Imaginate Festival. Where else would you find a show in which a boy made of cheese (from a planet made of cheese) floats down to Earth in a little wooden boat after his world is turned into fondue by a blazing comet?

Such is the premise of Finegan Kruckemeyer's splendidly quirky play The Tragical Life Of Cheeseboy (for children aged 10 and over), performed by the wonderfully unhinged Australian theatre company Slingsby. The story of Cheeseboy's epic search for his parents (who were separated from him by the comet incident) is worthy of its international acclaim.

Actor Stephen Sheehan brings the story to life in a delightfully eccentric and poetic performance. Dressed in dapper 19th-century garb, he plays under the canvas of a Victorian adventurer's tent, surrounded by exquisite period objects.

The young audience is enthralled as Sheehan, and his fine co-performer Sam McMahon, unfold the chapters of Cheeseboy's adventure, from his adoption by intrepid gypsies to the philosophical debate over whether it would be cannibalism for him to eat brie. The story takes various hilarious and mad diversions as it progresses, assisted by beautifully attuned music, crazy-yet-touching songs and lovely projected images.

As the play comes to its genuinely tragic end (Slingsby respect the intelligence and emotional sophistication of their audience), one is left profoundly impressed by director Andy Packer's fabulously stylish production. The show tours to Hamilton, Easterhouse and Glasgow's Tramway this coming week.

The Imaginate programme is always tremendously diverse, and it's hard to imagine a more different show from The Tragical Life Of Cheeseboy than Dutch company BonteHond's Lying Down (for audiences aged five plus). Not only is it about three sisters (Anna, Hannah and Susannah) trying to get themselves and their old grandmother to sleep, but it also invites its audience to sit or lie down on mattresses throughout the performance space. With incense burning and musician Jolle Roelofs tinkling the ivories, the theatre becomes the ultimate chill-out room.

At one moment, a pair of red shoes comes to life. At another, the cakes and tea in the kitchen appear to take on lives of their own. At such times, the excellent performers (Paméla Menzo, Feike Looyen and Charlene Schmeltz) show their talents for mime.

From fear of the dark and late night munchies, to toilet humour and matters of bereavement, director-creator Noël Fischer's production taps into the young mind with accuracy and sensitivity. The children are greatly amused by the antics of granny (represented by a large cloth puppet), not least when she falls asleep on the toilet. They are equally engaged but - and this is the show's real skill - never distressed by the subtle treatment of death. BonteHond was only established in 2005 and has already been nominated for a leading theatre award in The Netherlands. It isn't difficult to see why.

If the Australian and Dutch shows impress with their different approaches to design, Francis Gallop, set and props designer on Museum Of Dreams - the latest show (for kids aged 6-8) from Scotland's TAG theatre company - is similarly accomplished. In turning a small studio space into a tiny museum, he has created an enchanting environment for young children.

A series of glass exhibition cases are hidden behind beautiful curtains. As they are unveiled, the exhibits (from a tiny pair of shoes to a gramophone player) are revealed; one child at Glasgow's Citizens Theatre (where the piece premiered before transferring to the Imaginate Festival) almost stole the show by saying the 78 player was "what they played CDs on in olden days".

The premise of the show is that the museum attendant (the ever-excellent Keith MacPherson) is a somewhat slumbering fellow. As he sleeps, a little girl (represented first by a puppet and then by fine actress Deborah Arnott) invades his dreams. A thimble-sized child, she explores the exhibits, before dragging the attendant into her magical world.

It's a lovely concept, but realised in a stilted fashion. It's strange for a show of just 40 minutes to seem too long. One can't help but feel TAG's handsome production is a case of form triumphing over content.