Despite working on it, Ben Hurst (writer of the Sonic the Hedgehog (1993) and Sonic Underground series) considers it the worst work he has done on the character because originally for him it was always to do the third season of Sonic SatAM, which was previously canceled in 1995 and at some point. At the time of 1997 DIC company (the studio where the TV series for Sonic was made) announced Sonic Underground to which Ben Hurst quickly refused to participate in it because otherwise DIC would have turned it into the third season of Sonic SatAM but in the end he worked on it being the writer in some episodes to being the editor of the story, however he still couldn't make any changes or have his moments (as he did in Sonic SatAM) just write the story.
Knuckles the Echinda only appears in four episodes. These include Friend or Foe (1999), Flying Fortress: Chaos Emerald Crisis Part 1 (1999), No Hedgehog Is an Island: Chaos Emerald Crisis Part 2 (1999) and New Echidna in Town: Chaos Emerald Crisis Part 3 (1999).
This is not a sequel or spin-off of any of the other earlier "Sonic" programs, but a new series altogether.
The final Sonic the Hedgehog cartoon to have Jaleel White as the voice of Sonic. White also plays Sonic's siblings Sonia and Manic, as the characters are related, Triplets of Hedgehogs.
This show marks the first appearance of Knuckles in a mainstream television show. It is also the first show in which Tails, another major character, does not appear.