Zoo U is a game platform which implements performance-based assessment of social emotional (SE) skills through theory-driven content and customized game mechanics. Children engage with characters in a school-like story world to complete six virtual social situations specifically tailored to require the SE skills of communication, cooperation, empathy, emotion regulation, impulse control, and social initiation. Prior work established the scoring algorithms and construct validity for the six game-based scenes. In this study, we examined the degree to which social competence, as measured across the six Zoo U scenes, was related to school-based adjustment. As expected, children who demonstrated higher social competence when problem solving Zoo U's virtual situations were significantly more likely to exhibit positive social, behavioral, and academic adjustment, above and beyond demographic influences, and children who performed poorly on Zoo U were significantly more likely to experience negative school-based outcomes. The potential for game-based platforms to enable broad-scale SE skills assessment with children is discussed.