Rufus is actually from Elysium.
With the Identical Stranger situation and Captain Seagll claiming Rufus to be a "trash baby", I'm betting it'll turn out he came from there in the first place.- Jossed; he and Cletus are from a cloning facility on Deponia.
Goal and Donna were clones created in a predecessor to the Organon project.
They were specifically designed to interface ideally with brain augmentations; the plan was for all the Elysians to upload their minds to one or more supercomputers, while cryonically freezing their bodies (their brains were unable to survive the freezing process) or obtaining new bodies via cloning or robotics at a later date. For whatever reason, it didn't pan out, so we got Plan B, the Organon, instead.This would explain why, in Goodbye Deponia, Donna appears identical to Goal when dead or a child - she's naturally straight-haired and redheaded, and she was wearing Elysian clothing at the time of her death.
- Jossed again; the only reason Donna has an implant is that Doc put it there himself (which is why he has the remote to her implant in a drawer in his lab). That still doesn't explain the hair color change, though, or why Donna's clone's body couldn't be used as biomass to clone her back to full health again...
- Not so fast— just because Doc installed the brain implant doesn't mean it wasn't part of a bigger project. This theory could still be true, if we assume that Doc was in on it.
Deponia is actually Planet Earth in the distant future.
Why wouldn't it be? Deponians and Elysians are way too similar to humans than they are to any other humanoid race, save for the memory implants, but those could be a product of bioengineering and augmentations. There are even some small shout-outs to certain Earth countries, like the gondolier in the second game (Italy). Really, would it be too far-fetched to think that after centuries of polluting and producing trash, a cataclysm devastated Earth (regardless of whether or not it was man-made), and before that the planet was renamed Deponia as little to no past history survived and the old world was no more?