Challenge Acts are special missions unlocked by collecting Red Star Rings within each main stage. Each main stage has five Red Star Rings, and collecting them unlocks five unique Challenge Acts for that stage. These acts often feature unique objectives, such as racing a rival, defeating a certain number of enemies, or navigating a stage with specific limitations. Completing Challenge Acts rewards you with points, which contribute to unlocking new skills, music, and concept art. There are a total of 90 Challenge Acts in the game, offering a significant amount of replayability and skill-testing scenarios.
