Gamemaker Mind Candy Seeks Fresh Ideas as Its Moshis Age

Michael Acton Smith doesn’t like to act his age—at least in front of his customers. During a recent East London event for Moshi Monsters, his online game for kids, the 38-year-old turned up in a purple blazer, gripping a matching electric guitar with a bite mark on one side. Little girls in tutus and mermaid costumes lined up to sample treats from a milkshake bar and cupcake tower.

Like their creator, the misshapen, furry monsters that obsess kids in Britain and the U.S. are getting on in years. At five, Moshi Monsters are nearly as old as their 6-to-12 target audience. And the history of children’s media is littered with once-ubiquitous brands, such as Blue’s Clues and Teletubbies, that burn out as young fans age.