this one is for Lame:EZ
sonic was released as a seperate game on sega master system 2 in 1991. eventually it became the preinstalled game and replaced alex in miracle world. also have a book about sega that mentions the competition with the famicom (NES) and how sonic came to help sega.
i still have a sega MS 2 with sonic, alex kidd in miracle world (preinstalled) and alex kidd in shinobi world
check it out
best

