SEGA has just posted the above Sonic CD developer diary video on their blog. In the video Sonic Team Art Director Kazuyuki Hoshino gives an insight into the creation of Sonic CD‘s logo, characters, enemies, bosses and stages. It’s an interesting watch, and even features some never-before-seen concept sketches.
Source: SEGA Blog
Thanks to StrickerX-mas at the SSMB for the heads up!