Sonic the Hedgehog CD, or Sonic CD, is a 1993 platform video game in the Sonic the Hedgehog series, developed by Sonic Team for the Mega-CD/Sega CD. It marked the first official appearance of the characters Metal Sonic and Amy Rose. It was released by Sega in Japan on September 23, 1993, in Europe in October 1993, and in North America on November 19, 1993. The game has been critically acclaimed since release. The game was later ported to the PC in 1996 and was later included as part of the Sonic Gems Collection compilation in 2005 for PlayStation 2 and GameCube. An enhanced port was released on Xbox Live Arcade, PlayStation Network, iOS and Android in December 2011, and for PC on January 19, 2012. A Windows Phone version is expected Q1 2012.