I've never tried A.I.R. before. I know about it only from what I have read here. But here are my thoughts... If I understand correctly, you ported the game's logic into scripts as opposed to recreating it. I don't know what the law is on this or how much grey area there is, but that by itself sounds potentially problematic. Using the data from the ROM as opposed to packaging it with A.I.R. was smart, and certainly what others have done to make free alternatives to popular games. Using a diff file to recreate S3K content, I'm fairly certain, is still illegal. Don't quote me on that, but that just seems logical to me that it would be. I think I have also read as much. If it weren't, everyone would be doing it to distribute everything for free, even if only in RAM. You could consult counsel on this if you want to be certain on the matter, but I would honestly just assume it's a no-go. Another poster mentioned not making it your concern how the ROM was obtained. I say "bingo"! In my non-legal opinion, you've already crossed into questionable territory by porting the game's logic and then calling it free. That should be your biggest concern, not how someone obtains the data. Though I'm not sure A.I.R. is much more legal than the split disassemblies, and Sega hasn't gone after those yet. Feel free to correct any incorrect assumptions I have made.