Video games have tremendous potential in mathematics education, yet there is a push to simply add mathematics to a video game without regard to whether the game structure suits the mathematics, and without regard to the level of mathematical thought being learned in the game. Are students practicing facts, or are they problem-solving? This paper examines several schema for assessing how the structure of a video game interacts with the mathematical content. The schema include whether the mathematics is intrinsic to the structure of the game, and whether the game is epistemic, that is, whether players take on the identity of a mathematician or problem-solver while playing. Implications for future video games are discussed.