This innovative practice full paper describes sustainability teaching through game-based activities in engineering classrooms for potentially enhancing student interest in Science, Technology, Engineering and Mathematics (STEM) fields. Meta-analytic research indeed supports that gamification enhances student learning by increasing engagement and motivation, promoting goal setting behaviors and supporting the need for recognition. While there is a high scope for utilizing game-based tools to help students connect with global sustainability challenges, literature reflects a scarcity of such innovative pedagogical tools in engineering education. To tackle this challenge, we introduced interactive game-based modules to teach sustainability within two different education cultural contexts - one in the U.S. as a part of a Honours course at a large public university, and one in India, as a part of the first year engineering curriculum at a small private university. To broaden the outlook of engineering students towards sustainability, our game-based activity learning outcomes for students were to: 1) contextualize sustainability and its importance in contemporary global issues 2) recognize how Sustainable Development Goals (SDGs) could be interrelated, 3) explain how change in entropy and our actions can affect sustainability. To facilitate these broad learning outcomes, we developed two interactive gamified activities and implemented them online (due to COVID-based shift to instruction) in two different engineering institutions. This innovation article reports the design of two gamified activities used to teach sustainability, and studies its impact on student learning outcomes through SDT framework of motivation and thematic analysis of student reflections. We used surveys and minute paper to record student perceptions which were analyzed thematically. Results indicated that students enjoyed these games, saw value in peer learning, and simultaneously developed a deeper, more contextual understanding of sustainability by perceiving the interconnections between SDGs and ways in which entropy through their everyday actions influence sustainability.