What must Earth-3 residents think of the rest of the multiverse, though? Technically Earth-1 would be the world with their opposites. Is that a thing there?
Regardless of existential musings on the nature of evil doppelgangers, players can explore a variety of new bits of content on Earth-3, ranging from an open-world exploration of the new world’s Gotham City to an elite raid in which players rail against the Crime Syndicate that threatens the world. So go forth, find your evil opposite, and beat the living snot out of that villain. Or hero, we suppose, if your character is already a villain. It’s complex.