Mario Kart DS (styled as MARIOKART DS and abbreviated to MKDS), is a Nintendo DS racing game developed and published by Nintendo. It is the fifth instalment in the Mario Kart series and the first to use Nintendo's free online service, Nintendo Wi-Fi Connection (now discontinued as of May 20, 2014). The game was released in 2005. It was well-received critically, scoring an average of 91% from Metacritic. Many reviewers have called it the best Mario Kart game in the series. Like the other games in the Mario Kart series, Mario Kart DS involves various characters from various Mario games racing each other in go-karts on tracks themed from locations in the Mario series, less realistic physics, and the use of various weapons and or items to achieve victory differentiates kart racing games like Mario Kart DS from more realistic racing games. For US, Europe, Australia, and Japan it released in November/December 2005, apparently, if you live or lived in Korea, you had to wait until April 5, 2007.