Design Features Associated with User Engagement in Digital Games for Healthy Lifestyle Promotion in Youth: A Systematic Review of Qualitative and Quantitative Studies.

User engagement in digital (serious) games may be important to increase their effectiveness. Insights into how to create engaging games for healthy lifestyle promotion are needed, as despite their potential, not all digital (serious) games are highly engaging. This study systematically reviewed game features that were associated with higher user engagement among youth. A systematic search was conducted in PubMed, Web of Science, CINAHL, and PsycARTICLES databases. Qualitative and quantitative studies were included, if they documented game features associated with youth engagement. Coding of game features was performed using the mechanics-dynamics-aesthetics (MDA) framework. A total of 60 studies met the inclusion criteria and were included in the registered systematic review (No. CRD42018099487). Results showed that various game features were associated with user engagement in digital (serious) games: an attractive storyline, adaptable to gender and age, including diverse (antagonist) characters the user may identify with, high-end realistic graphics, well-defined instructions, which can be skipped, in combination with clear feedback and a balance of educational and fun content. This review underpinned the relevance of investigating engaging game features specifically for youth, as deviations were found with characteristics that are engaging for other populations.