For children to yield greater mental performance abilities in real world settings, training approaches should offer practice in problems which have an affective component requiring social interactions, and be motivating over a sustained period. Current cognitive training games often overlook the important relationship between cognition and emotion, characterised by ‘hot executive function’, and correlated with fundamental academic and life outcomes. Here, we present robust qualitative evidence from a case study which documents the social relationships, motivation and engagement of a class of ten-year-old children who used an active smartphone cognitive training game called BrainQuest in their physical education lessons over a period of 5 weeks. Game design elements which are intended to move beyond simple gamification of cognitive tests are presented, along with a discussion of how these design elements worked in practice. The paper also presents and discusses the impact of the game upon the cognitive and emotional regulatory skills, characterised by executive function skills, based on the findings of this initial work. We conclude with recommendations for the designers of cognitive training games in the future and discussion of appropriate research methods for future gamification studies.