libretro reicast does work on the pi, but the performance is trash.
I've been testing and the libretro reicast just works, isn't as functional as the standalone one, there are bugs and is slow. the only advantage is the naomi support.

EDIT: I should have said that is still experimental and you have to compile it yourself.

Great, thanks for testing this !

@johnodon the extra / is not an issue, issue here is that the core doesn't retrieve the path to your system directory (if it did, it wouldn't try to create this /home/pi/RetroPie/roms/arcade/dc/data directory). My only guess is that there is something wrong with your retroarch configuration/overrides for this core/game (system_directory should be set to ~/RetroPie/BIOS, systemfiles_in_content_dir should be set to false).

If you can't figure out what's wrong in your configuration files, a quick and dirty fix would be to create the /home/pi/RetroPie/roms/arcade/dc/data manually, you'll probably have to put system files in /home/pi/RetroPie/roms/arcade/dc too.

Also, make sure the core is up to date.

@ricko This is not related to RetroPie. I'm guessing you are using Emulation Station on Windows with MakaronEX. Wrong forum, sorry.

Thanks for the answers and clarification.

Can't have everything I guess.
Demul was open source at the very beginning but people didn't show any interest so they decided to lock the code and won't open it anymore. At least not anytime soon. Looks like pride is more important to them.

lr-fbalpha covers already so many awesome games which will keep us busy for quite a while.
I think besides that there is no emulator right now the other issue is hardware power. The Pi3 most like won't have the necessary specs to run any of those Atomiswave games.