Well what if I told you there was a device out there which enables the playing of pretty much every single Sega Mega Drive, Genesis, Sega Master System and 32X game through a single cart based SD in your Mega Drive! Welcome to the Mega Everdrive, a very interesting product sent to us by RetroTowers for review.
http://www.indieretronews.com/2014/12/mega-everdrive-sd-device-your-megadrive.html