Recognizing the growing value of game-based learning in medical education, this study aims to evaluate the effectiveness of the innovation, "Aquilibria: The Battle to Balance," a creative narrative card and board game to help improve learners' understanding and application of the concepts of acid-base balance. In this mixed-method study, 120 first-year medical students participated. The innovation employed a card and board style integrated with a captivating story. Students were divided into small groups of six each with a facilitator. Following this, the posttest was conducted to compare the educational gain. Also, students' perceptions about the game were obtained using a 32-item questionnaire on a 5-point Likert scale. In addition to this, the confidence level among students to understand and interpret the concepts of acid-base regulation before and after the game was obtained using a 10-item questionnaire on a 5-point Likert scale. Furthermore, for qualitative data, short interviews with open-ended questions were conducted and thematic analysis was performed. The results showed a highly significant improvement in academic performance from a pretest score of 7.57 ± 1.07 (means ± SD) to 16.14 ± 1.80 in the posttest with a P value of <0.0001. There was a notable increase in confidence among learners after the game, and highly positive student feedback was received. These findings support the growing recognition of narrative game-based learning as a valuable and engaging strategy in medical education, offering a promising avenue for fostering deeper understanding and retention of complex medical concepts.