This meta-analysis study aims to explore the game-based learning (GBL) effects on students' learning motivation and academic achievement in K-12 science education. Recently GBL has been broadly used for students with low learning motivation because the dynamic learning activities in computer games could provide benefits for K-12 education. We reviewed the recent decade (i.e., 2010-2019) studies of GBL and investigated the effect sizes for learning motivation (n = 35) and science achievement (n = 21) using the robust meta-analysis method. We found that using digital games can significantly increase students' motivation (g = 0.292) and science achievement (g = 0.475). The findings support the idea that GBL helps students have higher motivation and improve students' science achievement.