>>34552
Eggmanland was mentioned in the Japanese manuals pretty early on, actually, and "Robotnikland" made its way into some western licensed materials, too, separate from "Robotropolis" seen in SatAM and Archie. I remember I had one Gamebook all about Robotnikland. That said, GUN was pretty much entirely new to Sonic Adventure 2. There actually were many things showing Sonic interacting with humans in cities very early on, such as Waku Waku Sonic Patrol Car, which might be the second Sonic "game" ever made, but nothing implied the government to be as fucked up as GUN.
Also, the bit with the animals being turned into robots was always actually secondary, story-wise, to the story involving the Chaos Emeralds. But the western adaptations always ignored it and/or fucked it up. tl;dr: Sonic is basically an avatar of the primal force of Chaos, a chosen one destined to stop Eggman from controlling chaos. He does this in more and more literal forms (saving animals and plants, which also represent chaos, because life is chaotic, saving the chaos emeralds, which create all chaos), until in Sonic Adventure Eggman tries to control the actual God of Chaos. Sonic has always had an autistic story, but the localizers removed it.
>>34573
I suppose if I were to count those, they would contradict even each other, as in Unleashed and Colors, Eggman actually succeeds in making Eggmanland, and it is an amusement park, but then in Forces it isn't. I blame the furry terrorists (one man's terrorist is another man's "Freedom Fighter") that won't let Eggmanland be peaceful.
I wonder, how many times has Eggman killed an entire colony of scientists working for him, and their families with them? GUN has done it at least once. And Gerald's Diaries in Sonic Battle imply GUN had done plenty of fucked up stuff before that, like with Emerl.