© 2016 Mary Ann Liebert, Inc.Objective: This study investigated the effect of acute exergaming on the physiological and psychosocial responses of young adults and the modulatory effect of a single- or dual-player game play situation. Materials and Methods: Thirty-six participants (19 male; 21.7 ± 3.8 years; 23.65 ± 3.17 kg/m2) each completed two 30-minute exergame sessions in a randomized order (single and dual player) while wearing an Actiheart® to estimate energy expenditure. Positive and negative affect, subjective vitality, and indices of intrinsic motivation were assessed directly after each gaming bout. Results: There was no significant difference in energy expenditure or psychosocial outcomes between conditions. Although males expended more energy than females in both single- (z = -2.124, P = 0.033) and dual-player situations (z = -2.679, P = 0.007), females reported significantly greater vitality (z = -2.219, P = 0.026) and effort/importance than males (z = -2.001, P = 0.045). Conversely, males reported a greater negative affect (z = -2.872, P = 0.004) and pressure/tension (z = -3.295, P = 0.001). A linear mixed effects model revealed that energy expenditure during exergaming was a significant predictor of interest and enjoyment (P = 0.001) and effort and importance (P = 0.001). This relationship between energy expenditure and psychosocial variables was not modulated by sex or order of gameplay (single or dual player first). Conclusion: The present results suggest that females have a more positive psychosocial response to exergaming relative to males, highlighting exergames such as Wii™ boxing as a potential avenue for future interventions seeking to address the low physical activity levels that characterize the young adult population.