Mario & Sonic at the Winter Olympic Games sees big sales.

Mario and Sonic at the Olympic Winter Games screenshot

SEGA has revealed that Mario and Sonic at the Winter Olympic Games sold 5,670,000 units as of December 31, 2009, making it the publisher's biggest release of the year, and by some margin.

Bayonetta has fired her way to sales of 1.1 million units, a figure which according to SEGA's financial documents includes Japan, US and Europe - despite the game only being released in Japan during the reported tracking period.

The publisher's other hits over the nine month period ended December 31 were Football Manager 2010 and Phantasy Star Portable 2, shifting 740,000 and 540,000 units respectively.

We've contacted SEGA for clarification of the Bayonetta sales.