Effective waste management is crucial for sustainable living, but many individuals find it challenging to navigate the complexities of waste classification. This study presents a web-based serious game that utilizes interactive sorting quizzes, created by both users and AI, to promote environmental sustainability learning. The game incorporates AI-generated feedback, a carbon credit system, and user-generated content to engage and educate participants. Two user studies involving 48 university students were conducted to evaluate the game’s effectiveness. The findings suggest that the game effectively promotes learning and improves participants’ understanding of sustainable waste management practices. The results highlight the potential of serious games to encourage environmental education and sustainable behaviors, particularly when they incorporate user agency and community involvement. Using emerging technologies and engaging users, serious games can serve as valuable tools to promote sustainable practices and address environmental challenges.