"The Ballad of Proxima-B" is an educational RPG that promotes learning and collaboration. Students contribute to world-building and game mechanics, creating fictional worlds and characters, including a dystopian Earth, the planet Proxima-B, and alien races. The game incorporates constructivist, constructionist, and Dynamic Systems Model of Role Identity (DSMRI) principles. The hands-on and collaborative nature facilitates learning, reflection, and a strong classroom community. During gameplay, characters form alliances, encouraging students to reflect on their interactions. Design challenges include workload balance and addressing student anxiety. Game elements emphasize critical thinking and self-reflection, foster collaboration and community, and encourage exploring identity through serious play.