Onstage, a teenage girl is in the throes of emotional meltdown. Her best friend, who is confident and prettier, has helped play a cruel joke on her, and now the truth is out. The love letter from the desirable boy was a hoax. She waited and waited but he didn't meet her. As if to complete the gut-wrenching humiliation, he was still hot- dating her best friend.

The turbulent tale of adolescent Lieve is just one of the many told at this year's Imaginate Festival, a celebration of the performing arts for children. There are events for all ages, but the theatre for children aged 10 years and over is a wonderful mix of poignant tales of growing up and thundering emotions, with a touch of whimsy thrown in for good measure.

The self-styled ugly child in the play of the same name, Lieve is awash with hurt, anger and a rampaging need for revenge. In her own words, she's in "a black tunnel". And while some of the young audience probably squirmed in embarrassment at the upfront way this piece by Stella Den Haag (Netherlands) delved into the tidal surges of sexual awakening, conflicted self-image and self-doubt, the raw, perceptive honesty that yells its head off in Lieve's outpourings must surely have struck chords in others.

The risk-taking isn't confined to the subject matter. The text (handsomely delivered in English) deliberately veers between the extremes of Lieve's introverted, almost poetic, reading of an adult world she struggles to make sense of and her savagely abusive rants which flag up the incoherent rage that speaks of betrayed trust.

Then there's the music, not just threaded in as a reflection of varying moods, but an integral part of this rites of passage journey. Beatles songs, sung with a capella thoughtfulness, catch at the intensity of first love. Snatches of violin etudes offer glimpses of the beauty Lieve craves, not just for herself but for musically gifted Simone whose watermelon turns out to be a teenage pregnancy.

Ugly Child ( ****, Traverse Theatre, 10.30am today) is challenging, thought-provoking stuff - but then this would seem to be the hallmark of Stella Den Haag's repertoire.

A second piece, Thick Skinned Things at the Traverse Theatre (****) , run finished, saw Erna van den Berg - the director of Ugly Child - hunkering in semi-darkness and unburdening a surreal monologue about pathological shyness that borders on obsession. Nora the Mole - her own description - has literally gone to ground, tunnelling away from a society that unnerves her just as she, with her odd behaviour, has doubtless unnerved them. Knowing this has, if anything, driven her further underground. But there's a man. A stranger she once met ... and in the midst of this strange, haunted monologue, a glimmer of redemption flickers.

Again, this work for older children poses awkward and disquieting questions. It pushes hearts and minds towards darker territories, even as it encourages degrees of growing understanding. Uncompromising work - with no compromises either in the outstanding quality of the performances.

The Tragical Life of Cheeseboy (*****) , on until Sunday at Dance Base then Hamilton on June 2, Easterhouse on June 30 and the Tramway, June 4 and 5, is so achingly magical and charming, so full of whimsicality and merry eccentricity that when the reality of Cheeseboy's situation begins to strike home ... those with iron self-control will just swallow very hard. The rest of us will try to forage quietly for a hankie. Everything about this production by Slingsby (Australia) speaks of a loving attention to detail that acknowledges how children - this is also for the 10 years and over age group - are hawk-eyed and fond of quirky surprises. So right from the start, as we file into this self-contained tent, there's a sense that anything might happen. The attendants are vaguely in Victorian garb, the clutter - trunks, packing cases - looks intriguing. And when the story starts, complete with captioned projections, our best hopes are confirmed. Gosh, a planet made of cheese. How silly - but seconds later, the planet is fondue and Cheeseboy is adrift in space.

Tabletop models, pop-up props, eerily beguiling music and heartfelt storytelling make Cheeseboy's experience of loss and homelessness something so mythic and poignant you want to cry "stop" because he keeps travelling so hopefully, convinced his parents will find him. We know they're dead. But Cheeseboy doesn't. Loss after loss besets him, but even in adulthood he hopes to be found.

That this production, with consummate performances by Stephen Sheehan and Sam McMahon, turns what could be an unremittingly bleak scenario into something so life-affirming and uplifting is a marvel of exquisite theatre-craft. And what an incentive to eat Brie - if only as an aide memoire of this show.

Queen (***) at the Traverse Theatre, 10.30am today, saw Theater Sgaramusch (Switzerland) take genial, witty liberties with Scottish history as Nora Vonder Muhil and Gerhard A Goebel attempted to make a radio play out of the life and times of Mary, Queen of Scots. Lots of lovely visual gags gave a nod and a wink to how on-air sound effects are made. Lots of irreverent asides turned political conniving and personal tragedy into a rollicking farce. And yet, as he (playing Elizabeth of England) and she (in the role of Mary) argy-bargied over who should say what, there emerged a curiously strong sense of a power struggle that was made a nonsense of by the recording machinery itself. In the end, neither of them had control over the destiny of their play - how like history. Though whether the young audience - the 10 and over age group - thought of it in these terms is a moot point. They just roared with laughter. Sponsored by the Bank of Scotland.