Okay, so me and Hyper have been conversing and thought up the locations in our fanfic. They are from the Sonic series, and they are ones NOT included in Generations.

Sonic the Hedgehog~Labyrinth and Scrap Brain

Sonic the Hedgehog 2~Aquatic Ruin and Oil Ocean

Sonic the Hedgehog 3 and Knuckles~Hydrocity, Ice Cap, and Angel Island

Sonic CD~Palmtree Panic and Wacky Workbench

Sonic Adventure~Twinkle Park and Windy Valley

Sonic Adventure 2~Sky Rail and Pyramid Cave

Sonic Heroes~Mystic Mansion and Frog Forest

Sonic '06~Kingdom Valley and Radical Train

Sonic Unleashed~Apotos and Shamar

Sonic Colors~Aquarium Park and Starlight Carnival

Sonic and the Black Knight~Great Megalith and Titanic Plain

Sonic Chronicles~Voxai Colony and Nocturne

Sonic Advance 2~Music Plant and Ice Paradise

There we go. Here's all the main stages

REMEMBER~Only Cesar, Hyper and I are in the main team.