Poster-child for long-lived series Mario Party 8 set a milestone today, by Nintendo's reckoning: it's become the all-time fastest-selling title in the Mario Party series.

The Wii installment in the series sold 550,000 copies off U.S. shelves since it was originally released May 29—a period of nearly five weeks. It's likely that MP8 is playing off Wii's steady success, as the entry was built from specifically for the console (as opposed to being brought over from the now-dead GameCube) and features motion-controlled gameplay.