•Gamification is a promising avenue for enhancing user engagement.•Interaction with game elements facilitates basic psychological need satisfaction.•To foster user engagement, mobile apps should satisfy basic psychological needs.•User engagement with mobile apps leads to positive marketing outcomes. Organizations are increasingly making use of gamification to enhance users’ engagement with their mobile apps. However, more research into the mechanisms that facilitate user engagement and its consequences is needed. Drawing on the self-system model of motivational development, this study investigates how gamification might foster user engagement and positive marketing outcomes. Data from 276 users of a mobile gamified app were analyzed using partial least squares regression. The results showed that gamification increases user engagement through satisfaction of the needs for competence, autonomy and relatedness. User engagement, in turn, leads to greater intention to use, disseminate WOM about, and to positively rate, the app. Finally, this study provides a number of theoretical and practical implications that can help developers design more effective gamified mobile apps.