During January 2025, Chengxiang developed a foundational GameManager system for the Leyenda004/PMAP1 repository, focusing on gameplay stability and reliable state management. Leveraging C# and Unity, Chengxiang implemented a singleton-based architecture to ensure consistent GameManager behavior across scenes, supporting features like health management, level progression, enemy damage handling, and score and treasure tracking. The work included refining the game loop with continuous health drain and removing level-completion gating. Chengxiang also addressed codebase stability by reverting problematic merges and enhancing singleton robustness to prevent orphaned components, demonstrating a methodical approach to version control and maintainable game development practices.