The conceptual change approach has been a prevalent theoretical foundation for comprehending students' acquisition of scientific knowledge. Despite its extensive use, only a limited number of studies have employed this framework to examine the effectiveness of game-based learning (GBL). The GBL was utilized to teach 101 middle school students concerning bioaccumulation and biomagnification concepts. Concept cartoons were used for pre- and post-test to assess the extent of conceptual change. Students' reflections were employed to understand the emotional and social aspects analyzed by content analysis. The result indicated that before engaging in the GBL activity, most students had limited concepts of bioaccumulation (50%) and held partially accurate concepts of bioaccumulation without biomagnification (49%). After learning with the game activity, the students changed their concepts range from limited concepts to accurate concepts of bioaccumulation and biomagnification. The Wilcoxon signed-rank test revealed a significant change (Z = 2850, p[less than or equal to] 0.001), with an effect size of 1.00 indicating a large effect. This result provided evidence of the cognitive and the intentional aspects of conceptual change in which students extended their conceptions through GBL experiences. Furthermore, the students reported feeling joyful and expressed positive sentiments toward the learning activity and collaborative work.