In this study a courseware for a Chemistry subject -properties of matters- is developed. The coursewase was a kind of 2D game in which students study the subject while they are playing. Then it is applied to fifteen 7th grade (about age 14) students in real settings. As a result of the study it is found that the students’ post-test scores are significantly increased compared to pre-test scores when they study the courseware themselves. In addition, all students fill a usability form about the courseware. According to that, the score improvements of the students who found the courseware is usable are not significantly higher than the score improvements of the students who did not found it usable.