Developed a prototyping framework for unified player abilities in the endlessm/threadbare repository, focusing on integrating sword and grapple hook mechanics using GDScript. Built a dedicated test scene to validate input handling and enable rapid iteration on combined ability interactions, supporting scenarios such as swapping and equipping abilities. Introduced a repel grapple test level to assess simultaneous actions and puzzle-oriented gameplay, providing concrete validation for ongoing design proposals. This work established a scalable foundation for future gameplay features, improved test coverage, and reduced integration risk. Emphasized game development and level design best practices to enhance testability and accelerate iteration on core mechanics.