Fuerzabruta, Roundhouse/Walking with Dinosaurs -The Arena Spectacular, O2 Arena, review Drums crash in unison, strobe-lights flash, dry-ice engulfs the air, recurrent blizzards of white ticker-tape are whipped up by powerful fans. By turns a circus, carnival, techno rave, theme-park ride and initiation ceremony snatched from the jaws of hell, half the time you're thinking, "Did I really just see that?" A man in a white suit frantically runs on a treadmill, crashes through walls made of boxes and repeatedly gets felled by a shot to the heart. Scantily clad women splash and writhe about on water-filled, transparent platforms slowly lowered into the faces of the crowd, their bodies somehow flattened-looking as if in a James Bond opening-credit sequence. After a short time it seems entirely natural that the performers should execute dance-steps high above us, at right-angles to the ground, or whirl through space at speed on harnesses. If you can resist the odd grappling hand, you're safe from being whisked into full-on participation, although there's a lot less in the way of direct audience involvement than you might fear. The cast of 13, assisted by a fiendishly fast-working technical crew, do 99 per cent of the work and radiate an atmosphere of wild euphoria and erotic liberation even as they execute their hazardous, gravity-defying stunts. The only advice I'd give those hardy enough to take the plunge is to go with the hallucinogenic flow: your flutters of panic and whoops of excitement help motor an evening which, if it has a theme, is about reaching out and striving to find sparks of human connection in a disorientating world. President Cristina de Kirchner could usefully take note. Walking with Dinosaurs, the "Arena Spectacular," would be much improved by the immersive approach pioneered by the likes of Fuerzabruta. Sure, the 20-strong parade of life-sized beasts this spin-off from the BBC series rustles up - in a whistle-stop tour of a time when "the world was young and the dinosaurs were huge" - offers a useful sense of scale and a nice whiff of prehistoric verisimilitude, despite the obvious man-operated chassis the lumbering giants depend on. For all the amplified roaring and thrashing, though, there's little adrenalin-inducing sense of jeopardy or drama. Big but not clever enough. Fuerzabruta, until Jan 26. Tickets: 0844 482 8008; roundhouse.org.uk Walking with Dinosaurs - -The Arena Spectacular, tours until May 26: Tickets: 0844 856 0202; dinosaurlive.com