This study reports on the design and testing of an integrated suite of vocabulary training games for Nintendo[TM] collectively designated "My Word Coach" (Ubisoft, 2008). The games' design is based on a wide range of learning research, from classic studies on recycling patterns to frequency studies of modern corpora. Its general usage and learning effects were tested over a four-month period, with fifty age and level appropriate Francophone English as a second language learners in a Montreal school. A battery of observational and empirical tests tracked experimental and quasi-control groups' lexical development on the dimensions of form recognition, meaning recognition, free production, and speed of lexical access, as well as features of game use. Two months' gaming coincided with gains in recognition vocabulary normally achieved in one to two years, longer oral productions, reduced code switching, and increased speed of lexical access. Further questions are raised about the prior knowledge "Word Coach" assumes, the importance of post-game follow up, and the future of commercial gaming in language learning. (Contains 7 figures, 6 tables and 2 notes.)