Finding proper ways to address learning about sustainability is a relevant issue. Sustainability learning has to face some inherent complexities, due to two main factors: the interdisciplinary domains related to sustainability issues, such as ecology, economics, politics, and culture, and the involvement of several social structures, such as individuals, families, and communities. One recent research proposal is to exploit serious games to foster learning in this area. This resulted in a significant increase in the number of approaches discussed in the literature over the last few years. Notwithstanding this growing scenario, sustainability serious games still lack a reasoned evaluation, in order to clarify their possible applications and to define effective design strategies to approach them. To this end, in this paper, we investigate the current state of the art of serious games for sustainability, identifying, and discussing the most common applications. The research process included both scientific publications and unpublished materials. References were searched according to guiding questions, which helped focus the extraction of information, and through recursive browsing of their citations. Based on the research results, we propose a taxonomy for sustainability serious games and a classification of reviewed works according to this taxonomy. We also analyze design strategies, drawn from the literature, expressly conceived for the development of effective sustainability serious games. Finally, we discuss the current challenges and present possible areas of research in this field.