This is an Accepted Manuscript of an article published by Taylor & Francis in Children's Geographies on 2020, available online: doi 10.1080/14733285.2020.1853677Drawing on recent framings of young people’s environmental activism as a ‘game’, alongside long-standing characterisations of youth as responsibilised environmental change-agents, in this Viewpoint I identify fertile research opportunities in the liminal spaces between moments of young people’s action and the political and socio-cultural spaces through which those actions (might) diffuse. I argue that youth geographers should take care to engage critically with young activists’ actions, as well as wider political and cultural responses to them, in order to avoid furthering problema...