The GameCube is a home video game console released by Nintendo on September 14, 2001 in Japan and November 18, 2001 in North America. It was later released worldwide in 2002. The sixth-generation console is the successor to the Nintendo 64 and competed with Sony's PlayStation 2, Microsoft's Xbox, and Sega's Dreamcast. The GameCube is the first Nintendo console to use optical discs for its primary storage medium. The discs are similar to the miniDVD format, and as a result of their smaller size, the system was not designed to play standard DVDs or audio CDs. Nintendo presents a variety of connectivity options for the GameCube. It supports online gaming for a small number of games via the broadband or modem adapter, sold separately; and it connects to the Game Boy Advance, allowing players to access exclusive in-game features using the handheld as a second screen and controller. Contemporary reception of the GameCube was generally positive. Some praised the extensive software library and high-quality games, while others criticized the console's exterior design and lack of features. Nintendo sold 21.74 million GameCube units worldwide before being discontinued in 2007.