All over Edinburgh, venues large and small are currently hosting this year's Imaginate festival of performing arts for children and young people.

The programme, as ever, has a carefully selected tranche of international work. However, the remarkable opening show was a magical, wistfully whimsical piece for the 8+ age group by Unicorn Theatre from England. Called Something Very Far Away, it led its spellbound audience – adults too – on a journey to the very ends of the universe, and to the very deepest reaches of a loving human heart.

When a man suddenly loses his young wife, grief leads him to a peculiar appliance of science: if he can travel far enough into space, he will also travel back in time – to a point where back on earth, his wife will be alive. By filming scenes on three different miniature sets, using a beautifully-crafted mixture of cut-out silhouettes and shadow-play, as well as two delicately stick-thin puppets (as the devoted couple), the company create, and screen, his rocket-borne attempts to catch glimpses of her from distant galaxies.

There's a touching home-spun look to many of the models, as if young fingers had helped in their making. But the fanciful naivete of his space flight is really the product of much sophisticated invention, allied to a wonderful willingness to trust young audiences with a story that touches on death, but then gently shows how love transcends that loss in moments of cherished remembrance.

There's more space travel in the gung-ho shape of The Intergalactic Nemesis by The Robot Planet (USA). And again, the consummate skills of creators and performers surface through the cunning blend of modern technology with good old-fashioned graft-and-craft.

We're talking alien invasion in the year 1933. A huge screen fills with vivid frames seemingly drawn from a vintage comic book, three narrators voice all the characters (as in a radio drama) while the squish! wallop! crump! sound effects come courtesy of a hands-on Foley artist.

It's a gee-whizz sci-fi pot-pourri of Flash Gordon, Star Wars, B-movie monsters and mad-men plotting world domination and it corkscrews through some two hours of improbability with such energy, the 8+ audience were gripped, as if the evil Mysterion had them hypnotised.

Alles (All) is a finger-clicking, foot-stomping, shimmy-shaking, funny-noises-making dance-around for four to seven-year-olds performed by Het Lab (Utrecht). Two dancers – one male, one female – play rhythmical games with shapes and sounds, moving slithery arms and legs in response to their own accomplished range of vocalisations. No set, no props, until near the end. Just as you're wondering if they can keep things as fresh and inventive after 40 minutes of non-stop activity, they go cheerfully mad with slap-stick paint.It's clever, often funny stuff but what really impresses is how they keep a sense of connection and involvement with the audience. We applaud very rhythmically afterwards.