In this study, mixed research methods were adopted to examine the online game-based learning environment for" Go Go Bugs." The purpose of this study was to determine if an online game-based learning environment can engage and motivate students to learn more natural science by using game features than the control group, which had the same learning environment, but no game features. This experiment examined the engagement by participants? frequencies of returning to the learning environment after school hours, within a time period of two weeks. The results of the comparison of pre- and post- surveys showed significant improvement in increasing participants? interest in learning natural science in a game-based learning environment over that of the non-game-based learning environment. Both quantitative and qualitative results from this study indicated that this game-based learning environment successfully motivated participants in exploring natural science and engaging in the learning activities. However, there was no significant result showing that the game-based learning environment improves students? learning achievement more than with the non-game-based learning environment.