By March 2011 , the Sonic games had sold more than 80 million physical copies .
Spin-offs have explored other genres , including racing games such as Sonic R ( 1997 ) and sports games such as Mario & Sonic at the Olympic Games ( 2007 ) .By March 2011 , the Sonic games had sold over 89million physical copies by March 2011 , and grossed over by 2014 .
Sonic the Hedgehog