**5. Conclusion**

Presently, researchers and clinicians expect to apply the combination of MI and BCI to a great range of users for rehabilitation purposes. Thus, existing challenges in current MI-BCI works must be solved, such as training issues. This review has utilized the majority of SR to present a scientific and objective review of one potential solution, gamification, to optimize MI-BCI training outcomes. Our finding through evidence (28 articles, 111 individuals with accuracy test, 74.35% average accuracy, 26 out of 28 positive responses) shows that using the MI-BCI game for training could be feasible.

The result also recommends 2D avoiding obstacles game, 3D Cybathlon game, and VR humanoid first-person action game as prior MI-BCI games for further research. Moreover, this review maps the cautions of the current issues of gamified MI-BCI training mode and the potential methods to overcome them. The literature review is predicted to provide a new vision of the appropriate gamified MI-BCI training modes and what elements, such as metrics and issues, are suggested to consider for scientific research.

