Environmental sustainability education should create eco-awareness and produce pro-environmental behaviors. Traditional instructional methods create eco-awareness but do not make people act. Purposefully designed digital games for attitudinal instruction provide cognitive knowledge, engage learners emotionally by showing the consequences of harmful behaviors, and encourage correct behaviors. Most studies involving games in different subjects showed that knowledge acquisition was greater in collaborative learning than individual game play. However, a similar comparison with respect to attitudinal learning involving a socio-scientific topic has not been conducted before. This mixed methods study conducted in a high school in India, examined the attitudinal learning among students who played a game individually (n = 45) and collaboratively (n = 44). Also, differences between students who played the game and a control group (n = 42) was examined. Surveys based on the Theory of Planned Behavior (TPB) and the Attitudinal Learning Instrument (ALI), showed that attitudinal learning from games was similar for collaborative and individual players. Also, attitudinal learning from games was higher compared to traditional instructional methods. Interviews explained the learning experiences of game players and how it produced pro-environmental behaviors.