You just choose from a number of different characters in Mario’s world, such as Luigi, Donkey Kong, Wario, Waluigi, Princess Peach, and Daisy, and race around a variety of tracks in different karts. As you cruise along, you can pick up some weapons to help disrupt your opponents or give yourself a speed advantage, and you can also unlock more tracks, karts, and characters by winning races. Since Mario Kart DS is such a big hit, it’s often hard to find in stores because it sells out so quickly. But don’t worry; there are several other ways to get your hands on this great game. First of all, if you want to save up to 50 percent off the retail price, you should check out stores that sell used video games.