Mario Kart 8 made its debut on Wii U and found some success, but the console's small install base limited its potential. Nintendo opted to re-release it on Switch with new content (including some often-requested multiplayer modes), and the results have been staggering. In its first year on the market, it quickly outsold the original Wii U version, and those numbers are still steadily climbing.
According to Nintendo's latest sales figures, Mario Kart 8 Deluxe has now sold over 10.35 million copies. Meanwhile, the Wii U version as sold 8.42 million copies. Individually, Deluxe has now outsold Super Mario Kart, Mario Kart 64, Super Circuit, and Double Dash. If you count both versions of 8 as one game, its sales total 18.77 million, which would also top the 17.21 million achieved by Mario Kart 7 on 3DS. Mario Kart DS (23.6 million) and Mario Kart Wii (37.10 million) are still miles ahead, but Deluxe will have plenty of time to catch up as Switch sales continue to climb.