Digital learning environments have been gaining prominence during the last few years. In particular, the rising usage of mobile devices, including smartphones and tabs, has invited researchers to design and develop learning applications and games for such platforms. Mobile applications and games have been developed for learning languages like many other domains. However, most of these games are fun-based and lack a holistic design and development approach. Therefore, as a principal contribution, this research presents a theoretical model for designing language learning games in a cultural context. The proposed model combines the elements of sociocultural theory with the concepts and elements of gamification, keeping in view the requirements and educational settings, including level and mode of education, etc., to ensure the effectiveness and usability of the developed game. Subsequently, based on the proposed model, a Language Learning Game (LLG) has been designed and developed through a systematic process that involves game design, low-fidelity, and high-fidelity prototyping and its validation. The LLG has been evaluated comprehensively at different stages by incorporating standard methods. Whereby this research augments the existing set of heuristics by proposing a number of specialized heuristics for the evaluation of serious games to gauge their conformance to the cultural context. The evaluation results show that the game has overall usability scores of 90%. While the quasi-experiment-based pre-test and post-test have been conducted, the results reveal that the results obtained by LLG are statistically significantly better than adopted mobile application and traditional group.