I have released the full official GEMS development kit for developing your own Megadrive music. I also released an unreleased game/demo called Ship that I compiled from the additional source code included in the floppy. More info can be found here: http://www.hidden-palace.org/?news/c/13 Enjoy! I will be soon recieving all the dev equipment that is required to get the Megadrive part to run, I will then post some pictures of how it works and maybe even program an emulator, so you can fully utilize this kit.
Nice release. Just a shame that most of the games listed on the Wiki that use GEMS are all ones with IMO, shit audio Yakumo