The BBC said,
Rounds included "what links these two famous people", fill in the bleeped out words from a clip, puns, and little rants. The show was best near its end - we listeners at home could play along with "What's that sound?". and laugh as the panel tried to indicate words by making noises.
Sound Mate sagged a bit in the middle, but that's why they do pilots. There's plenty to build from: the opening round was entertainingly bizarre, and the show ended with plenty of silliness.