I got all the ROMs out and compared them to GoodGen. All of them match save for one. It looks like someone grabbed these ROMs from the internet, rather from Sega's own archives: There are two text files in the ROM folder. ECCO.TXT appears to be a placeholder description for the Ecco listing. SONIC.TXT is actually a carbon copy of this: http://www.angelfire.com/ny/dezmoowu/Sega/megadrive.txt I backed everything up on Hidden Palace for safe keeping. Thanks for the release!