Correct. The license (at least, the one I read for Red Alert) is GPLv3 with some additional stuff. The additional stuff is mostly about not using EA trademarks in your version or showing any connection to EA itself. So it appears that a clean room asset swap would be allowed as long as it includes the title screen.
I’m assuming this is more about art assets. Art is not code and you shouldn’t expect them for free. It’s not a catch.
Correct. The license (at least, the one I read for Red Alert) is GPLv3 with some additional stuff. The additional stuff is mostly about not using EA trademarks in your version or showing any connection to EA itself. So it appears that a clean room asset swap would be allowed as long as it includes the title screen.