Updated: Nov 23, 2019
ROM preservation seems to be all the rage lately which is a great thing! A Sega Genesis / Mega Drive Prototype rom was recently dumped on 11-20-2019. Crying Dragon : Gensou Senki Kokou no Ryuu is an action side scrolling RPG originally announced for the Mega CD in 1991.
The game itself is far from finished as there is absolutely no sound and all the foes appear as a jumbled glitch. This is suspected to be a very early build of Crying Dragon as all of the information fit on the developer cartridge. "This game's code doesn't touch Mega CD anything. It's likely the game was abandoned long before any Mega CD-specific parts were written.", writes Pietro Gagliardi of https://andlabs.dev/blog/crying-dragon/ who also aquired and dumped the rom.
For more backstory, gameplay, and information check out the blog in the link above.
If you want to see the gameplay in action now check out this video.