Legal reasons prevent Clive Anderson admitting the similarity between this Edinburgh hour and a certain Channel 4 improv show of the 80s and 90s. Let's just say fans of Whose Line Is It Anyway? will find much to enjoy, and memories stirred, at the extemporising antics of Josie Lawrence, Greg Proops and co. There's so much love in the room, and these improv old-timers are so effortless, it feels like there's no way for this show to fail – which is somewhat contrary to the improv spirit. But tonight's performance is undoubtedly a hoot, as the Whose Line veterans dance in ever more ridiculous shapes to the audience's tune.
There's no deviation from the TV format. The first game requires the team to speak to one another exclusively in questions; the next is freeze tag, which gets a bit too gynaecological when Lawrence ends up on her back, legs apart. Master of ceremonies Anderson nips each exercise peremptorily in the bud, when sometimes they'd benefit from time to escalate or breathe. (The show is twice as long as its TV forebear.) The playing space is unnecessarily narrow too, which tends to keep things verbal and limit room for manoeuvre.
But there are some helpless laughs here, at the spectacle of four grownups celebrating their submission to the audience's whim. One scene finds Colin Mochrie and the suave Proops improvising a hunting scene to sound effects supplied by two volunteers – whose efforts they mock mercilessly. Another ascends into chaos to meet the ongoing requirement that its performers be respectively standing, sitting, bending and lying down. Some satisfying pay-offs, too, are supplied by Lawrence's terrific improvised singing – a skill that her three colleagues are yet to master. Tonight it feels like the team is coasting – but even on cruise control, they unleash big laughter.
• Until 19 August. Box office: 0844 545 8252. Venue: Underbelly Bristo Square.
• This article was amended on 11 August 2014 to remove a reference to "legs akimbo".
