The aim of this study is to make a new attempt to explore the potential of integrating game strategies with automatic speech recognition technologies to provide learners with individual opportunities for English pronunciation learning. The study developed the Game Embedded CALL (GeCALL) system with two activities for on-line speaking practice. For the drill practice, learners get immediate scores with evaluation feedback on their utterances; in the game-based practice, they have to correctly choose and pronounce the English vocabulary from the candidate answers to pass the four-level barriers. To enable the study to confirm the factors that facilitate students' English learning, a total of 52 learners from Taiwan participated in this experiment, divided into an experimental group (E.G.) and a control group (C.G.). The learners in the E.G learned English with both the drill and game-based practice, while the students in the C.G. learned only with the drill practice. The empirical evaluation reveals that those who learned with both drill and game-based activities performed better in terms of their English pronunciation than the learners who only participated in the drill practice, but the learners in the C.G. performed better in the delayed vocabulary retention test. Besides, the study indicates that the learners, especially the low-achievement ones, showed great involvement and were active in practicing speaking in the game-based scenario. The findings are in accordance with the previous research affirming that gameplay is the driving force that promotes learners' educative engagement, and that learners of different levels of learning achievement are active in learning together while practicing their oral speaking in the stress-free environment. In sum, the GeCALL system is an educative aid that could reduce learners' language speaking anxiety and to provide flexible chances for individual students to do self-speaking practice within the given limited teaching time. The findings of this study support the value of applying game strategies with ASR techniques for language learning purposes.