Mario Kart is oddly one of those Nintendo franchises that fans love to complain about, yet continually buy. The tweaking between each new iteration can be maddening to many fans, but it is what keeps the franchise fresh. Still, some fans weren’t quite happy with Nintendo’s development track and they released their own version for the PC. Based on the Source engine that powers Half-Life 2, Mario Kart Source may not be much to look at, but the gameplay sure seems to be there in spades.