The document discusses the challenges of creating effective educational games that truly teach students. It notes that while games are good at engaging and motivating students, most games do not actually teach in a valid way. The document outlines some of the key elements needed for a teaching game, including being a valid assessment, providing scaffolding for students, and incorporating multiple representations of concepts. It then discusses one game called Mars Generation One: Argubot Academy that was created to teach argumentation skills and how it incorporated design elements like precise assessments, masterable complexity, and an emotional journey to transform students' thinking. However, it notes a challenge is the significant resources needed to create such teaching games at scale.