AFAIK there are no humans in sight other than Eggman, I wonder why.
Not just in Colors, but in IDW Comic series, Lost World, and Sonic Forces too.
Have you forgotten The Adventure, '06 and Unleashed games? Humans are present on Sonic's world. My fantheory/headcanon is that humans simply outpopulate mobians by a lot.
A
long time a go, it was believed that Sonic games take place on an alien planet with Dr. Eggman as the only human. Japanese manuals never refered to it directly but western manuals called it Mobius. Over time the name Mobius caught on with the early cartoons at the time.
By Dreamcast, the established lore was thrown out for a revised lore saying Mobius was never a thing and that Sonic lives on Earth. However unlike our
Earth, this
Earth had different geography, advance human cultures, various phenomena and an
eldritch Cthulian horror sleeping within the heart of the planet.
Since Dreamcast, this has caused somewhat of a division between how Sonic fans prefer their games, this division wouldn't be "propely labeled" until Sonic Generations introduce the eras. But it's mostly accepted that Sonic games have always taken place on an alternate paralell Earth different from ours.
At least, that was what was established up until Sonic Colours when in an interview Takashi Iizuka said that Sonic's world and Earth has always been seperate and various games either take place in one or the other.[
*]
Given there is no evidence of Sonic going to and from seperate worlds, this caused a brand new rift in the fandom. One-worlders like me who believe/prefer it was always a single alternate Earth for Sonic games and Two-worlders who believed in the more classic Mobius and Earth being seperate thing.
One-Worlders like myself bring up lots of contradictions to this statement. If Sonic 3 & Knuckles takes place in Sonic's world and Sonic Adventure takes place on Earth, why is Angel Island present in both games? Why is the Mystic Ruins on Earth? Takashi Iizuka's excuse is "some miracle brought it there." I think eventually Ian Flynn confirmed that the two-world statement was redacted and that it has always been the one world for Sonic.
But there were some who took the two-world statement as figurative, I did. Like how the "Wizarding World" of Harry Potter. The Wizarding World is not a seperate planet from Earth where sorcery resides in. It's simply a term to refer to the hidden magical community of wizards and witches who live secret and seperate lives from non-magic people to the point it feels like separate worlds to them.
I like to believe that humans and mobians share the same planet which they call Earth. Humans outpopulate mobians which is why throughout Adventure, '06 and Unleashed we see humans everywhere but hardly any mobians other than Sonic and his friends. But I believe mobians simply prefer more secluded communities than humans, perhaps island-life such as the islands from the Classic-era of Sonic games.
This theory is somewhat supported in Sonic Forces where the World Map depicts a large island. This moves onto my second theory that this island is actually a modern take on South Island. My evidence:
- Green Hill = Green Hill Zone
- Mystic Jungle = Jungle Zone (and a bit of Labyrinth Zone)
- City = Spring Yard Zone (The very least the city can be seen in the background, but both zones are urban zones that use warm colours.
- Metropolis = Star Light Zone (I always thought Star Light Zone looked like a giant construction site. So I imagine Metropolis is the finished work of Star Light Zone and what it would look like during day time.)
- Eggman Empire Fortress = Scrap Brain Zone (8-bit Sonic 1 shows Scrap Brain located on the highest mountain of South Island. And given MArble Zone shows the island to be volcanic means the mountain is likely a volcano. In Sonic Forces, Eggman's fortress is located on a volcano-like mountain on the World Map. So I am guessing Dr. Eggman turned what's left of Scrap Brain into his Empire Fortress.
And that pretty much covers about a third of my theories on the nature of Sonic's world.