Season 1 Episode
- Season 1 Beginnings (Origins, Part 1)
- Season 1 To Catch a Queen
- Season 1 Mobodoon
- Season 1 The Price of Freedom
- Season 1 Underground Masquerade
- Season 1 Tangled Webs
- Season 1 The Deepest Fear
- Season 1 Who Do You Think You Are
- Season 1 The Last Resort
- Season 1 Come Out Wherever You Are
- Season 1 Winner Fakes All
- Season 1 A Hedgehog's Home Is Her Castle
- Season 1 Artifact
- Season 1 Bug!
- Season 1 Sonic Tonic
- Season 1 Friend or Foe?
- Season 1 Head Games
- Season 1 When in Rome...
- Season 1 The Jewel of the Crown
- Season 1 Three Hedgehogs and a Baby
- Season 1 Dunes Day
- Season 1 Mummy Dearest
- Season 1 Hedgehog in the Iron Mask
- Season 1 Six Is a Crowd
- Season 1 Flying Fortress (Chaos Emerald Crisis, Part 1)
- Season 1 Wedding Bell Blues
- Season 1 No Hedgehog Is an Island (Chaos Emerald Crisis, Part 2)
- Season 1 Getting to Know You (Origins, Part 2)
- Season 1 New Echidna in Town (Chaos Emerald Crisis, Part 3)
- Season 1 Harmony or Something (Origins, Part 3)
- Season 1 Country Crisis
- Season 1 Haircraft in Space
- Season 1 Healer
- Season 1 Sonia's Choice
- Season 1 The Big Melt
- Season 1 Sleepers
- Season 1 Bartleby the Prisoner
- Season 1 The Art of Destruction
- Season 1 The Pendant
- Season 1 Virtual Danger
Sonic Underground - Season 1 Episode 35 The Big Melt
6.90 25 minutes The Hedgehogs vacation is interrupted by the news of Robotnik's latest weapon. They are shocked as the submarine melts the icy landscape from under their feet. The Hedgehogs then scurry to locate the lethal submarine before the entire planet is completely submerged underwater.
