This paper examines how the heterogeneity of K-12 students, as game audiences, affect the way games can beused as educational tools in formal education. When discussing the application of games in educational contexts, the realitiesof the formal educational environment are seldom brought to the fore. There has been a lot of discourse and studiessurrounding the theoretical viability of games as engaging educational tools and their properties as learning environments,but the practicalities of inserting games into classroom environments are comparatively rarely the subject of game-basedlearning research. This paper presents two five month long studies using participatory observation that details the processof putting a commercial of-the-shelf game to use in two different types of formal educational K-12 environments: a computerlab and a classroom. More specifically, this paper focuses on examining how students receive and work with a well-knowncommercial off-the-shelf game when it is introduced as a tool in their ordinary curriculum work. The study revealed severalchallenges that put many of the axiomatic assumptions practitioners and scholars frequently make regarding games’ virtuesas educational tools into question. The challenges relate to students’ perceptions of games and gaming, variations instudents’ efficacy while playing, and of exclusionary behaviour during collaborations. Commercial of-the-shelf games, whilethey might be more equipped than educational titles when it comes to living up to player expectations as far as productionvalues are concerned, can instil a certain set of faulty expectations of how the game will actually be used. If the used gameis widely recognisable by the classroom audience, the important distinction between gameplay intended for active directedlearning rather than unguided leisure activity can be difficult to establish, which can make it difficult for teachers to keepstudents in a reflexive and analytic mode of play. The classroom as a game audience also puts the educator in a tricky positiondue to the wide variation of preferences and gaming literacy among students, and creating engaging play-sessions that areinclusive to everyone in classroom environments can be an immense undertaking for teachers. While the study revealsseveral issues produced by the tension between games and the heterogeneous nature of the classroom as an audience, italso highlights the importance of managing students’ expectations, framing the play activity correctly, and fosteringcollaborative work where subject matter knowledge and gaming literacy are intertwined.