Games have been shown to be highly effective in education. Consequently, game-based learning is attracting more attention from researchers. However, the existing game-based learning systems lack the effective learning method required to provide a proper review strategy for the enhancement of learning. This paper proposes a game-based learning system using the graduated-interval recall method to organize game contents and learning courses with appropriate review intervals according to learning status. The evaluations were conducted on the proposed system at Gwacheon National Science Museum in Korea with children visitors. The validity of the proposed system was verified by an analysis of the experimental data.