Sega are chill with Sonic, though I recall you once reported they put the hammer down on a Golden Axe fan project once.
Yeah, SEGA still sent C&D letter to fan games sometimes but it never went into the court.
I dunno about Sony and Microsoft but they're more for the console itself. If someone is pirating PlayStation 1-2 or XBox original-360 games, then I think that's left to the developers or producers legal team. I think.
Okay, may be takes example of Capcom, Bandai Namco, or SNK Playmore then.
They're really chill with mods or M.U.G.E.N characters and stages using their assets.


