There are some games that were released for the Sega Dreamcast and did not get any port, which means, 'till this day, only dremcast owners are able to play certain games like:
Confidential Mission
D2
Death Crimson 2/ OX
Elemental Gimmick Gear
Evolution
Evolution 2
Gunbird 2Illbleed
Mars Matrix
Metropolis Street Racer
Record of Lodoss War Advent of Cardice
etc.
Couldn't Sega get in touch with the owners of those IPs and to re-release them in a special bundle or something ?
Unfortunately some of the companies who developed/produced/published those games don't even exist anymore.
Some of those games deserve a second chance.