The most alarming moment in Mark Haddon’s young adult novel is when Christopher Boone, a 15-year-old on the autism spectrum, flees his Swindon home for London. After a perilous train journey, he arrives at Paddington station and is overwhelmed. The book’s text becomes a barrage of fonts and type sizes to express the information overload: announcements, shop signs and adverts all shouting for his attention.

That sense of cacophony, a sensory assault of products, people and places, characterises Ned Bennett’s ambitious new staging of the Simon Stephens adaptation for Birmingham Rep and Melting Pot. Eleanor Bull’s bare stage, an outsize studio in white, alternates between clean geometric lines, such as the row of pastel-coloured houses that form a picture-book street, and more detailed high-definition projections.

Hayley Egan’s excellent video design lays out everyday objects – wrench, tampon, wooden spoon – for careful study as if in a Dorling Kindersley illustrated hardback. It makes the familiar seem strange and demanding. The busy percussive score by Giles Thomas only offers more to process, while a multitasking ensemble drift in and out, surreal and playful, police officers one minute, tumblers the next. There is much to take in, much to make sense of.

At the vulnerable centre, a gender-swapped Chris (Alex Keenan) gets to Paddington and is plunged into a storm of bouncing balls – all yellow, her hated colour, all bearing advertising slogans and all trying to knock her off course. It is a clever theatrical representation of Haddon’s literary idea: Chris v an unfathomable world. To make it on to a tube train, she has to master a skipping rope, as if navigating the city were like making it through an adventure playground.

Elbows high, head tilted, Keenan captures Chris’s combination of bewilderment and cheeriness. She is puzzled by human interactions, certain in her love of maths and science. In a high-energy professional debut, she charms with her enthusiasm enough to carry us through the distressing times when Chris turns inwards or lashes out as facts and emotions become too much to process.

Fun and inventive, Bennett’s staging has the dreamlike quality of something created before our eyes. Sex, death and infidelity are handled with matter-of-fact sensitivity as we cheer Chris for triumphing in the face of adversity.

• Touring until 28 May.