Fleetway Publications used the original SEGA material to create an appropriate continuity for their comic. Here Robotnik once was Kintobor, who used the Chaos Emeralds to build a machine that should remove all evil from Mobius forever, and when the machine exploded he was turned into the evil Robotnik. Archie Comics based their continuity on the Sonic the Hedgehog cartoon series instead.
In the first issues, Archie mostly tried to adopt the slapstick storytelling
from the syndicated version of the two existing Sonic cartoon series, called
"Adventures of Sonic the Hedgehog". Beside Sonic, Tails and Robotnik
this cartoons also featured Robotnik's stupid henchmen Scratch, Grounder and
Coconuts, who didn't pose much threat to anyone. Most fans agree that this
series had low-quality artwork and inferior plots, mainly designed to
entertain very young viewers. This is also the reason why the early Sonic
comics until around issue #20 aren't all that hot.
Fortunately, Archie Comics realized after a while that this was a move
in the wrong direction, and so they slowly started to change course and
publish more stories that followed the other, more popular cartoon version
instead, which was simply called "Sonic the Hedgehog". In contrary
to the syndicated cartoon, this one had great artwork, a darker, more
thrilling atmosphere, cleverly-planned plots and a continuous storyline
which was liked by both younger and older Sonic fans alike.
However, since the early stories in the Archie comics were mostly
one-parters with simple plots where nothing was gained or lost (similar
to the stories in the very first Fleetway issues), Archie started late
with establishing a real continuity. And unlike Fleetway, where things
were laid out early (namely in issue #8, "The Origin Of Sonic"),
Archie spread Sonic's history over many issues, explaining everything
in 'flashbacks', only revealing small bits at a time (similar to how
it was done in the movie "Highlander"). Although not everything
has been revealed yet, the final result obviously turned out a little
different than the one shown in the cartoon.
Click here to read more about history from Sonic's point of view.
Fleetway Publications made Knuckles the supreme guardian of the Floating Island, who knew all its secrets and ancient history, but had no knowledge where his people went and why they left him alone to watch over the island. Since Archie had originally planned to use Knuckles only for occasional 'guest appearences', they didn't give much thought about his origin during the first stories featuring him. But with the reader's growing interest in the red echidna, this soon changed.
Like Sonic's past, Knuckles' past was also shown in 'flashbacks', spread over many issues. By now, Knuckles almost seems to be more popular than Sonic is among American fans; he even got his own ongoing comic series. However, unlike the Knuckles from the Fleetway Sonic series, this one is not nearly as self-assured; he is still learning how to fit into the role of a true guardian, and discovering new secrets about the Floating Island and the history of his people in almost every issue.
Click here to read more about history from Knuckles' point of view.