We developed an Academic English Competitive Mahjong Game (AECMG) to help learners improve the understandings of academic English via a gaming process. In addition, an empirical study was conducted to examine how learners reacted to a single-player game (SPG) and multiple-player game (MPG) from the perspective of task difficulties. The results indicated that the difficulty of the tasks did not significantly affect the learning performance but increased learners’ task time and mistakes during the gaming process. On the other hand, learners with the MPG had better task scores and used fewer hints, regardless of the easy or difficult tasks. Furthermore, learners with the SPG checked the answers at the beginning of the task to collect more information while those with the MPG checked the answers after re-ordering the cards `without collecting learning information. These findings suggested that learners with the SPG had more intrinsic motivation to gain additional understandings while learners with the MPG had extrinsic motivation to pay attention to gain external bonus. Based on the aforementioned findings, we developed a framework, which can contribute the understandings of the impacts of competition on learners’ motivation.