There were two Sonic shows before Underground: The Adventures of Sonic the Hedgehog (AoStH) and Sonic the Hedgehog (SatAM). SatAM was similar in setting to Underground. There was also a film, entitled Sonic the Hedgehog The Movie (Sonic OVA).
Sonic Underground, I believe
well the freedom fighters are shown in Sonic the Hedgehog series and Sonic Underground series. both series are tv series.
Sonic Underground
It is unlikely that Sonic underground will get a continuation due to it being cancelled as a result of viewers dropping it.
AOSTH: no Sonic X: yes Sonic SATAM: no Sonic underground: no
Maybe they cancel the series
Sonic Underground is an animated TV series. And no, you cannot unlock episodes, or characters other than Sonic, from Sonic Underground in Super Smash Bros Brawl.
As of 2021, there have been four animated TV series based on the "Sonic the Hedgehog" video game franchise: "Adventures of Sonic the Hedgehog," "Sonic the Hedgehog" (also known as "SatAM"), "Sonic Underground," and "Sonic Boom."
Not in the canon series. In Sonic Underground he is an orphan, but in the games he doesn't have a backstory
If you mean finish the story they have the next series coming out March 2013 check details on Retro Sonic >>>Sonic Underground To Be Continued...In Comic Form.
No,but who knows? They never finished the Series,it ended at Episode 40 I think.
If you mean series as in TV series, then there are 4. Adventures of Sonic the Hedgehog (best show ever.), Sonic the Hedgehog (also called Sonic SatAM), Sonic Underground, and Sonic X. The first 3 shows were made by Dic, and Sonic X was made by 4kids.