This paper reports on a project that draws upon the framework of the community of inquiry to support game-based language learning outside classroom. Case study design was employed to collect and analyze both qualitative and quantitative data, with a view to investigating the participants' language development, participation, and perception. This study spanned a 6-week period and involved 11 intermediate English learners in China. The volunteer participants played an interactive adventure game in an out-of-class setting, with the instructor present and scaffolds available online. Results showed that the participants gained statistically significant vocabulary development and believed they made progress in listening and reading. Moreover, it is found that the participants were the most active in the first two and final weeks. The findings also showed general satisfaction and improved learning autonomy, highlighting the pivotal role of the instructor. The paper concludes by discussing its limitations and identifying future research directions.