As built environment educators we develop educational tools to support youth’s learning and engagement especially in the context of the urban environment. One focus of our work is to design games that link playful pedagogical approaches with urban contents. Whereas previous literature gives various practical examples for applying games in the context of both built environment education and participatory urban planning, there is a lack of research addressing the question of how games can foster critical thinking about the urban environment – an essential competence for rethinking and reshaping urban spaces. Therefore, we conducted a three-year educational design research project, and developed the game ‘Urbanity’ in order to explore how a critical approach can be integrated into the urban game design. In this chapter, we present the resulting design principles in triangulation with the existing literature: dialogue, reasoning, pluralism, openness, and situatedness. These design principles can serve as guidelines for future game developments, assist built environment educators, game designers, and urban planners, and steer further discussion.