Thünderbards introduce themselves as "Britain's least diverse comedy sketch duo". This is, after all, two young white men performing skits that encapsulate that mainstream worldview. As such there are funny, decent ideas here, with sequences imagining a dating app for people in a witness protection programme, or the consequences of putting on an all-male version of Grease. The jokes are decent and a lot is crammed into the hour. The duo's interaction is well-honed, and the whole is a slick piece of stagecraft. There's a running gag about infidelity that gives a loose cohesion, but there's little investment in making the whole thing hang together. Instead this is a promenade of well-executed sketches that show deftness in developing comic ideas.
But while the duo mock their lack of diversity, they never overcome it, or manage to develop a comic style or worldview that they can call their own. They argue over whether comedy has to say something about society, and this too feels like performers heading of criticism without actively responding to it. In their personae they recall a young Fry and Laurie, and they sit squarely within such comic traditions without troubling them. It feels a little mean to give three stars to a show that is well put together, showcases writing talent, and has many good gags. But they really need to find something particular that defines them in order to stand out from a Fringe overflowing with sketch shows.