When I read most of the episodes script at naosth.com, none of them took place on earth & there was no humans, but however some of the episodes are from the game, but it didn't took place on earth. Why is the naosth cartoon is barley like the segasonic games?
It's loosely based on the pre-SA American version of Sonic from 1993 or so, nothing from SA is in the cartoon, and very little sometimes to do with the games.

~ SA Tails