The generation who have had experienced computer games while growing up, are called game generation. The game generation has quite different styles of thinking and behavior from other generations. But present education methods for the game generation are not basically different from the education methods for other generations. Prensky argued that digital game-based learning is one of the few ways to meet the needs of the information age for the game generation. In this paper, we analyze the suitability of 4 design methods for educational games in comparison which were selected by the literatures survey. The suitability analysis was performed on the overall design method, the game design method, the education design method, the explicit of the design method, and the pros and cons. We suggest research topics on design methods for educational games which are needed to research in the future, based on the analyzed results.