The concept of an active and experiencing learner in an environment where knowledge is constructed through activities such as games is a constructivist approach to learning. GBL is an approach that engages students in a topic, makes learning enjoyable, and motivates learning both inside and beyond the classroom. 'Scimazing Game', an outdoor game-based teaching-learning technique, was developed for a high school Science class in order to assess students' success and to allow them to have fun while still developing information and skills. The 'Scimazing Game' technique resulted in an increase in the pupils' exam scores. Additionally, the students' pre- and post-test scores were compared using the paired t-test, which revealed a significant difference. Similarly, the three variables pertaining to the students' profile, namely their sex, age, and general weighted average, demonstrated no significant correlation with their academic achievement. This finding bolsters the growing interest in game-based teaching-learning strategy and management as a very effective medium for teaching and learning. 'Scimazing Game' provides a diverse method and unique resource to assist students in improving their academic performance in Science.