The Sega CD, known as the Mega-CD in most regions outside North America, is an add-on for the Sega Genesis, released in 1991 in Japan, 1992 in the United States, and 1993 in Europe. Due to the growing popularity of CDs, along with dedicated consoles based around the CD format such as the CD-i and 3DO, Sega saw fit to release an add-on for the Genesis that allowed developers to take advantage of the format. It included beefier hardware that allowed for sprite scaling and rotation and a faster CPU, and allows for playing of standard audio CDs in the system. The biggest benefit to developers was added storage, allowing for over 300 times the space of a standard Genesis cartridge, allowing for the playback of CD quality music, full motion video (FMV), and more.
The add-on was received quite well for its time, and many quality games were released for the add-on, such as Sonic CD, Popful Mail, Snatcher, and Lunar: Eternal Blue. However, the system was infamous for receiving tons of low quality FMV games, such as Sewer Shark, Corpse Killer, and the infamous Night Trap, which was a main target of controversy which led to the ESRB being created.
The system sold roughly 2.25 million units by 1996, when it was discontinued. Retrospective reviews have been more mixed toward the add-on, praising it for its games and some of its abilities, but criticizing it for the tons of low quality FMV games, lack of deep games, and high price.

Sega consoles

• Sega Master System
• Sega Genesis (Mega Drive)
• Sega CD (Mega-CD)
• Sega 32X
• Sega Saturn
• Sega Dreamcast