"Sonic Adventure 2" was developed by Sonic Team USA, a former American division of Sonic Team, and published by Sega. It was directed and produced by longtime series contributors Takashi Iizuka and Yuji Naka respectively. Development began shortly after the release of the American version of "Sonic Adventure" in September 1999, and lasted 18 months. It was designed to be more action-oriented than the slower, more story-based "Adventure". The development team ran the game at 60 frames per second with "tempo", giving Sonic a variety of actions rather than focusing on speed alone. Its levels facilitated this flow, making Sonic seem faster. All six playable characters have roughly equal gameplay time (unlike "Adventure", in which some characters had short stories).