Mario & Luigi: Partners in Time is the second game in the Mario & Luigi RPG series, released in 2005 for the Nintendo DS. In this game, Mario and Luigi find themselves in the strange position of traveling back in time and working with their infant selves to save the Mushroom Kingdom. This is the perfect pun and title for the game.

It combines "Partners in crime" with the game's time-travel theme. "Partner in Crime" expresses the idea of close friends who get into all kinds of trouble together, which is a perfect match for the two Mario Brothers.