These identify the Windows builds I used, if you want to compare versions. You will need Linux builds on SteamOS.
retroarch.exe SHA256 bc6070d9c0db493f9174ccbb30cd6cba2fccd5102beb071ae2d72bca073ba921
flycast_libretro.dll SHA256 e0a95c8a2e1adb98d153a016f2139c0a8fadc4352091f803a4116e0e4fc47710
