Princess Peach Showtime puts Princess Peach center stage in a theater-themed adventure where she takes on different performative transformations, from swordfighting to detective work, to save a troupe from a villain. Each act plays with its own mechanics tied to that costume.

Levels are built like stage productions, with platforming, light puzzle-solving, and simple combat shifting depending on which role Peach adopts. The presentation leans into a colorful, theatrical tone throughout.