Creator Backlash: Ben Hurst expressed a contempt for writing for the series, disliking the premise and having a bad time working with the material of other staff. To add insult to injury this was pitched in favor of continuing his previous beloved project, Sonic Satam.
Cross-Dressing Voices: Jaleel White as Sonia. Oddly though, if one watches an episode of Sonic Underground, you can tell the voice Jaleel White uses when providing the voice of Sonia sounds inconspicuously identical to the high-pitched voice White used from his other (more) famous role as Steve Urkel.
What Could Have Been: More episodes of this show were planned, but never went beyond the planning stages. We can only wonder how it could have ended. Ian Flynn, current head writer of Archie Comics' Sonic the Hedgehog, has stated that he would like to write a conclusion in comic form (helped by the fact that the cartoon was established to be in the comic series' Multiverse in an earlier story), but Executive Meddling means that there are some issues are going to have to be dealt with first.
At first, it seemed he would finally get to make that ending. It was even briefly advertised to be in the fiftieth issue of Sonic Universe. However, a different story ended up taking that slot, and the conclusion went through Development Hell before it was eventually cancelled. A summary of the story will appear in "Lost Hedgehog Tales," a collection of Ian's planned and scrapped stories.