Sonic the Hedgehog O

Sonic the Hedgehog O is Star Crash Inc.'s classic style Sonic the Hedgehog game. It contains elements from Sonic the Hedgehog 1, 2, 3, & Knuckles, Spinball, and Adventure. It is considered an "alternate universe" from the main series.

Story

The game loosely follows the plot of Sonic the Hedgehog 1, 2, 3, and & Knuckles. At the end of each game's plot points, Dr. Eggman escapes to another island, eventually messing with Knuckles and making him an enemy of Sonic. After defeating Knuckles twice and driving Eggman towards his lair, Knuckles helps him. (Amy has also been helping Sonic.) Eventually, they (along with Rouge and Mighty who they have befriended) encounter Eggman at his Death Egg. They find out he has built the giant Egg Emperor, and infused it with a helpless and supercharged Chaos. After defeating the Egg Emperor suit, it crashes into the lab holding Eggman's super-realistic hedgehog android, Shadow. Shadow's wires latch onto the Emperor Suit and power it up. Even Eggman has to help a little to stop it from destroying his labs. Afterwards, Sonic goes home and Eggman reforms. However, upon collecting all seven Chaos Emeralds, the Chao Graveyard is revealed where the supercharged Chaos has been lurking. Being fused with the Emperor Suit has mad it go insane. Upon defeating it, peace is truly restored. At the end of the secret credits unlocked from beating him, you see the Shadow android wake up to see a bright light...

Gameplay

The gameplay is similar to that of the classic Sonic games, showing your character from the side. No homing attacks or similar actions are present. The only playable character is Sonic on the first run through. After you beat a level, you can play as any of your partners you encounter throughout the game in that level (Tails, Amy, Knuckles, Rouge, or Mighty.) Each one has their own skills. Partners, when you are not playing as them, follow you around. In 2-player mode, the second player can play as your current partner or after you beat the level any one of your unlocked partners. During the Robot Death Zone (in which all of your partners are present) they can choose who to be even before you beat the level. The graphics are new like in Sonic the Hedgehog 4, Sonic Colors, and Sonic Generations. However, there are not many distracting visuals in the backgrounds.

Levels

South Island

• Green Hill Zone
  • GHZ 1
  • GHZ 2: Egg Ball'n'Chain
• Marble Zone
  • MZ 1
  • MZ 2: Egg Block Hands
• Wind Works Zone (contains Chaos emerald)
  • WWZ 1
  • WWZ 2: Egg Teleport Chamber

Main Isle

• Emerald Hill Zone (Tails joins)
  • EHZ 1
  • EHZ 2: Huge Dozer
• Power Plant Zone
  • PPZ 1
  • PPZ 2: Huge Bucket
• Aqua Ruins Zone
  • ARZ 1
  • ARZ 2: Huge Hammer
• Casino Nights Zone
  • CNZ 1
  • CNZ 2: Huge Pachinko
• Hill Top Zone
  • HTZ 1
  • HTZ 2: Huge Climber
• Mystic Caves Zone
  • MCZ 1
  • MCZ 2: Huge Firebot
• Oil Ocean Zone (Contains Chaos Emerald)
  • OOZ 1
  • OOZ 2: Huge Octopi

Echidna Isle

• Grass Valley Zone (Tails leaves, Amy joins)
  • GVZ 1: Egg Doomship
  • GVZ 2: Knuckles
• Robot Waters Zone
  • RWZ 1
  • RWZ 2: Missle Cage
• Chaos Chamber Zone
  • CCZ 1
  • CCZ 2: Chaos
• Egg Lair Zone (contains Chaos Emerald)
  • ELZ 1: Pseudo-Sonic
  • ELZ 2: Dr. Eggman

Floating Island

• Mushroom Hill Zone (Amy leaves)
  • MHZ 1: Waterbotnik
  • MHZ 2: Woodchucker Bot
• Mole Airship Zone
  • MAZ 1: Captain Mole
  • MAZ 2: Main Cannon
• Knuckles Zone
  • KZ 1: Mighty
  • KZ 2: Knuckles
• Space Cannon Zone (Knuckles joins, contains Chaos Emerald)
  • SCZ 1
  • SCZ 2: Rouge

Tall Tower

• Toxic Caves Zone (Contains Chaos Emerald)
  • TCZ 1: Mr. Cluck
  • TCZ 2: Wrenchgator
• Abstract Mechanism Zone (Contains Chaos Emerald)
  • AMZ 1
  • AMZ 2: Mechanism Operator

Death Egg

• Robot Death Zone (contains Chaos Emerald, Tails Amy Rouge and Mighty join)
  • RDZ 1: Mecha Sonic
  • RDZ 2: Egg Emperor Chaos Edition
  • RDZ 3: Shadow Emperor Android Chaos Edition

Special Ruins

• Chao Graveyard Zone (requires all Chaos Emeralds to unlock, all party members leave)
  • CGZ 1: Chaos Chaocage
  • CGZ 2: Perfect Chaos

Trivia

• The name refers to the fact that the game is a full circle, containing story and characters from later on in the series without going overboard and playing through the stories from the original plot to a modified Adventure.
• The game's story is an alternate universe from the main Sonic series.
  • An example of this is the fact that Shadow in this game is an android.