"Mario & Sonic at the Olympic Games may have gotten a lukewarm critical reception (its average review score is 6.2) but it has been an incredible success with consumers. The mash-up of SEGA and Nintendo properties has sold upwards of 10 million copies worldwide on Wii and DS, and continues to sell well some 16 months after release. Work on the obvious follow up, Mario & Sonic at the Olympic Winter Games, began immediately after the first was completed in November 2007. Fans can expect a similar but more robust experience when it ships later this year. It's still a very casual sports game, but it is already showing polish and the Wii balance board has been implemented well. "