I’ve played Rebellion, thanks to the GOG version. I would have played Supremacy, but it’s not on GOG, it doesn’t run on 64-bit systems and the sites hosting fanmade patches disappeared a few years ago.
Is there any difference between the two other than the name?
Not that I know of. But like I said, I can’t tell, because GOG only has Rebellion and all the fansites with utilities that let you patch the game yourself for 64-bit systems are dead.