The game features a total of 16 characters (including Mario and Sonic) who compete in various olympic events divided into four categories emphasizing 1) all-around, 2) speed, 3) power, and 4) skill. Each event makes use of the remote and nunchuck in different ways to compete. Similar to Super Mario Kart, each character has its own skillset and strengths distribute amongst the the four aforementioned categories. The game makes use of the WiFi connection to post and display results to and from a leaderboard so you can compare your results against other gamers.
There are 20 authentic Olympic events falling under 8 categories: 1) athletics, 2) gymnastics, 3) shooting, 4) rowing, 5) archery, 6) aquatics, 7) fencing, and 8) table tennis. You can compete in each of these event in either tournament, circuit, or a single-player mission mode.
Mario & Sonic at the Olympic Games was released for the Wii in November, 2006 worldwide, and will be coming to the Nintendo DS in January 2008.