 Seeking to create an add @-@ on device for the Genesis , Sega developed the unit to read compact discs as its storage medium . The main benefit of CD technology was greater storage capacity , which allowed for games to be nearly 320 times larger than their Genesis cartridge counterparts . This benefit manifested in the form of full motion video ( FMV ) games like the controversial Night Trap , which became a focus of the 1993 Congressional hearings on issues of video game violence and ratings . Sega Enterprises partnered with JVC to design the add @-@ on and refused to consult with Sega of America until the project was completed . Sega of America assembled parts from various " dummy " units to obtain a working prototype . While the add @-@ on became known for several well @-@ received games such as Sonic the Hedgehog CD and Lunar : Eternal Blue , its game library contained a large number of Genesis ports and FMV titles . The Sega CD was redesigned a number of times , including once by Sega and several times by licensed third @-@ party developers . 
