Game-based learning environments hold great promise for engaging learners. Yet game mechanics can initially pose barriers for students with less prior gaming experience. This paper examines game-based learning for a population of middle school learners in the US, where female students tend to have less gaming experience than male students. In a pilot study with an early version of ENGAGE, a game-based learning environment for middle school computer science education, female students reported higher initial frustration. To address this critical issue, we developed a prototype learning companion designed specifically to reduce frustration through the telling of autobiographical stories. In a pilot study of two 7th grade classrooms, female students responded especially positively to the learning companion, eliminating the gender gap in reported frustration. The results suggest that introducing learning companions can directly contribute to making the benefits of game-based learning equita...