In computer game development, establishing parameters for the ‘3C’ elements (Character, Controls, Camera)—including character appearance, movement mechanics, human-computer interaction designs, and camera behaviors—during the pre-production stage is critical for producing high-quality gameplay. However, comprehending the impact of parameter adjustments can be challenging, particularly for novice developers who must struggle with programming from scratch while studying adjustment processes. Furthermore, conventional educational resources rarely offer interactive demonstrations of how adjustments influence the gameplay experience. To address these issues, we introduce ‘JumpLab’, an interactive educational tool designed to teach the impact of parameter adjustments. JumpLab provides interfaces for modifying various parameters that control player character jump trajectories and camera behaviors in platform games. JumpLab operates in web browsers, allowing users to study parameter descriptions while controlling characters and experiencing the impact of parameter adjustment in real-time.