When intercepting Drakken and Shego's latest plan to swipe a mystical monkey idol from a spooky mansion, Dr. Drakken and Ron Stoppable get their minds switched! The idol is quickly lost, and Kim Possible and her arch-rival Shego reluctantly team up to get it back and set things back to normal.
Kim Possible: What's the Switch? is a side-scrolling 2D platformer with visual similarities to Klonoa 2, excluding the ability to change the paths you take. The camera follows Kim (or Shego) as you progress through various levels - while it plays like a 2D platformer, it gives the illusion of 3D. The main goal of each level is to get to the end of the level; however, there are also sub-goals of collecting all the Kimmunicator tokens within a level (which unlock concept art amongst other things), and collecting the Club Banana tokens hidden in secret spots (which unlock new outfits to wear).
Shego and Kim control quite similarly, in that they can both perform kung-fu attacks, backflips and double jumps. Later on, they both gain the ability to use a grapple and EMP bomb to disable special enemies. In addition to this, Kim has super sticky gum which can be used to snag enemies and control switches remotely, while Shego gains a magnetic power to move metal objects from far away.