The thought came to mind when discussing robot combat in my first thread.
The cooperative mode of a certain game came to mind, and I thought an adaption for this game could be fun. Something to unlock after playing the game to a certain point, to be determined.
Main idea is to unlock a cooperative mode, which would have some different puzzles in different specific rooms of the castle. It would allow things like synchronized button pressing, or specific timing events. Doing it in a room format would allow patches in the future to add more rooms to try.