In this study, we investigated and compared solitary and collaborative modes of game-based learning in promoting students' science learning and motivation. A total of fifty seventh grade students participated in this study. The results showed that students who played in a solitary or collaborative mode demonstrated improvement in learning outcomes. No significant difference was found between the two modes in terms of learning motivation. However, our qualitative results revealed critical insights into our understanding of the effectiveness of game-based learning. Game-based learning encourages students to explore science concepts explicitly and mindfully; furthermore, learning supplemented with collaborative learning can enrich the learning experience and collective problem solving that brings students to the next level of learning. The findings from this study may provide guidelines for what works in the context of game-based learning.