The MANCOVA results indicated significant improvement of the mathematics achievement of the experimental versus control group. No significant improvement was found in the motivation of the experimental versus control group. However, a significant improvement was found on the motivation scores of the students who played the games in their school lab and classrooms compared to the ones who played the games only in the school labs. In addition, the findings indicated that prior mathematics knowledge, computer skill and English language skill did not play significant roles in achievement and motivation of the experimental group. Teachers’ interviews revealed that these individual differences had indeed played significant roles in game-playing at the beginning of using the games, but the impacts gradually diminished as the students gained the required game-playing skills.