Nintendo's has confirmed that Mario Kart 8 has sold 8 million copies since launch.

The popular racer launched in 2014 and has become the Wii U's biggest commercial hit. What makes this achievement all the more remarkable is that the Wii U has only sold 13.36 million units to date.

Elsewhere, Super Smash Bros. for Wii U has shifted 4.99 million copies and Splatoon has sold 4.57 million units. Super Mario Maker - another recent release - has retailed 3.73 million copies.

The 3DS has now sold 61.57 million units globally, with PokΓ©mon X & Y (15.64 million) and Mario Kart 7 (13.94 million) remaining its top-selling titles. Super Smash Bros. for 3DS is the most recent best-seller, with 8.35 million copies sold.