While educational games have been increasingly popular in education, insufficient studies have comprehensively reviewed their effectiveness. To complement this missing link, this study explored game-based learning outcomes including academic achievements, problem-solving, and critical thinking abilities, knowledge, learning efficiency, skills, student attitudes, and behaviors. Both negative and positive effects of educational games on motivation were also explored based on comprehensive literature analysis. The role of engagement in game-based learning was studied, coupled with the ways to enhance student engagement. We also explored the importance of gamified components in student satisfaction and provided constructive suggestions for designers and practitioners. Future research should highlight learning analytics and data mining techniques of educational game-based learning and try to find out solutions to address various problems to improve the effectiveness of educational games.