This study examines the general assumption that serious games can bring about positive effects for purported social changes. The interactive nature of the serious game was thought to be one of the distinctive aspects of the medium as compared with other traditional non- interactive media. To explore whether the interactivity of serious games yields different psychological influences, we conducted an experimental study with a serious game whose narrative concerns the environmental issue, EcoFriendz (N=40). The results illustrate that those who played the video game perceived themselves to be more aware of the environmental problem than those who read the same narrative in a non-interactive text format. Also the game players were more willing to carry out measures to deal with the environmental problem.