Sonic Underground
Sonic, Manic and Sonia must fight Dr. Robotnik and his two sidekicks, Sleet and Dingo and the SWAT Bots, with the aid of their metal medallions and bring peace to Mobius and find mother!
Wedding Bell Blues
Robotnik announces that he will marry Queen Aleena in a plot to become the king of Mobius.
To Catch a Queen
Argus, a captain of the Queen's guard, is captured by Sleet and Dingo before he can reach the secret rendezvous where he was to meet Queen Aleena.
Mobodoon
Sonic, Sonia, and Manic return to their birthplace, Mobodoon, a beautiful, festive town.
The Price of Freedom
Sonia travels to east Mobius to visit her friend Mindy at the LaTour estate.
Underground Masquerade
Sleet and Dingo plan to collect the taxes owed to Robotnik from the Duke of Velcronia but keep it for themselves.
Tangled Webs
The sinister Robotnik blackmails Cyrus, an old friend of Sonic's, by holding his father hostage.
The Deepest Fear
On a trip to Port Mobius, Sonic, Manic, and Sonia are told that ships are sinking due to the Mobian sea beast.
Who Do You Think You Are
Queen Aleena's royal journals are rumored to be buried under a palace in the city of Tashistan.
The Last Resort
While lost in the wastelands of Mobius, Sonic, Manic, and Sonia stumble upon an oasis called Lake Valley Resort.
Come Out Wherever You Are
Sonia is invited to a debutante ball, but before she can be officially announced to society, she and her brothers, Manic and Sonic, have an important mission.
Winner Fakes All
Robotnik organizes a track meet to lure Sonic into a trap.
A Hedgehog’s Home Is Her Castle
The Hedgehogs receive a message they believe is from their cousin.
Artifact
The Hedgehogs steal historical artifacts of Mobuis from Robotnik before he can pawn them off at an auction.
Bug
A faction of the Freedom Fighters is wiped out by a swarm of metallic fly-bots.
Sonic Tonic
A speed enhancing fluid deemed Sonic Tonic is created by Robotnik to make him as fast as Sonic so that he may finally catch him.
Friend or Foe
The Hedgehogs converge on the Floating Island, in their latest attempt to find their Mother.
Head Games
As Sonic begins to chow chili dogs for a snack, he finds a message in the sack from his mother urging him to head to Speedster Island.
When in Rome...
Sonic becomes frustrated that maybe all of their efforts of fighting for freedom seem futile.
The Jewel of the Crown
Robotnik has his sights set upon Queen Aleena's crown jewel, which glows as it is moved closer to her.
Three Hedgehogs and a Baby
Sonic, Manic, and Sonia find an abandoned baby in an alley and begin a search for the baby's parents.
Dunes Day
Sonic and his siblings travel to the outskirts of Mobius to recruit a tribe of nomads for the Resistance.
Mummy, Dearest
Sonic, Manic, and Sonia invade Robotnik's lair to retrieve the Hedgehog crest.
The Hedgehog in the Iron Mask
The Hedgehogs' latest quest to find their mother takes them to the prison tower, where they encounter a masked stranger who insists he is family.
Six Is a Crowd
The Oracle advises the Hedgehogs to undertake a mission that could reveal answers about their future.
Flying Fortress
What is supposed to be a vacation for Sonic, Manic, and Sonia turns into a battle to save Mobius when Robotnik attacks with his newest weapon – the Flying Fortress.
Beginnings
The history of the Underground is told in detail, from the fall of Mobotropolis to the rise of Robotnik.
No Hedgehog Is an Island
Sleet and Dingo escape the Flying Fortress with the Chaos Emerald.
Getting to Know You
The Hedgehogs begin to learn the important lessons of what it takes to be a freedom fighter.
New Echidna in Town
Knuckles reluctantly makes a deal with Robotnik to turn over Sonic and his family in exchange for finding the Chaos Emerald that will save Mobius.
Harmony or Something
Manic, Sonic, and Sonia must end their training early when Robotnik threatens the Oracle and takes a member of the resistance hostage.
Country Crisis
Queen Aleena advises the Hedgehogs to travel to a valley of Mobius so that they can bring about peace between two contingents of the resistance that have split.
Haircraft in Space
Robotnik is using the local hairdresser, Doo-bot, to get information on the citizens who are against him.
Healer
A self-proclaimed scientist has come to Robotropolis with a device that will reverse the effects of Robotnik's robotisizer.
Sonia's Choice
Robotnik has arranged a museum exhibit of the Royal family goblets.
The Big Melt
The Hedgehogs vacation is interrupted by the news of Robotnik's latest weapon.
Sleepers
On a mission in a distant sector of Robotropolis, the Hedgehogs are informed that freedom fighters have disappeared and are going to be robotisized.
Bartleby the Prisoner
Robotnik captures Bartleby and uses him as bait to capture Sonia.
The Art of Destruction
Robotnik's new weapon, Art, is the enforcer of Robotropolis new eradication policy.
The Pendant
The newly discovered Emerald Peninsula is a perfect place for Robotnik to add slaves to his empire.
Virtual Danger
Sonic and Manic play a game of virtual reality to enhance their pilot skills.
