Sonic the hedgehog is the first game in the timeline because it is the first game
Sonic the hedgehog 2 is the second game in the timeline because it is the second game
Sonic 3 & Knuckles is the second game in the timeline because is the third game
Sonic CD is the 4th game in the timeline because it introduces Amy Rose and Metal Sonic.
Sonic Advanced is the 5th game in the timeline because it happens before Sonic Advance 2
Sonic Advanced 2 is the 6th game in the timeline because it introduces Cream the Rabbit who has a cameo in Sonic Adventure DX so this game has to happen before Sonic Adventure
Sonic Adventure is the next game in the timeline because it's the next mainline sonic game
Sonic Adventure 2 is the next game in the timeline because it is the next mainline sonic game
Sonic Heroes is the next game in the timeline because it follows up Shadow's death in sonic adventure 2
Shadow the hedgehog is the next game in the timeline because it follows up on heroes plot point of Shadow being a robot
Sonic battle is the next game in the timeline because Shadow is in it and he knows he's not a robot, which was established in Shadow the hedgehog, and it introduces Emerl
Sonic Advanced 3 is the next game in the timeline because one of the antagonists is a robot based on Emerl from Sonic battle
All the Sonic Riders games take place here because they're cannon to the timeline because Sonic Frontiers references them. They're spinoffs and they can basically take place at any time between Shadow the Hedgehog and Frontiers
Sonic 06 is next in the timeline because it is the next mainline entry in the franchise and it introduces silver into the franchise
Both sonic rivals games are next in the timeline because the events of sonic 06 were erased from existence and this reintroduces silver into the timeline
Sonic and the secret rings is next in the timeline because it gets referenced later in Sonic Generations
Sonic Unleashed is next in the timeline because it introduces Orbot into the timeline
Sonic and the black knight is the next game in the timeline because in Sonic Unleashed, there is a dialogue choice where sonic can choose to schedule a date with Amy. At the end of Black Knight, it is revealed that Sonic is telling Amy the events of the game as an explanation for why he missed their date.
Sonic colors is the next game in the timeline because it introduces the wisps and cubot into the timeline
Sonic generations is the next game in the timeline because it directly follows up on what happened to Eggman following his defeat in Sonic colors
Sonic lost worlds is the next game in the timeline because it introduces Zavok into the timeline
Sonic team racing is the next game in the timeline because all of the characters in the game have been added to the timeline now and this game gets referenced in frontiers for some reason so it's cannon
Sonic Mania is the next game in the timeline because it is a prequel to Sonic Forces
Sonic forces is the next game in the timeline because it is the next mainline entry and Zavok is in it so it has to happen after lost worlds
Sonic Frontiers is the next game in the timeline because it is the most recent mainline game in the franchise, references numerous old games, and introduces Sage into the timeline
The Murder of Sonic the Hedgehog is the next game in the timeline because it is the only other game at this time to have Sage in it
Sonic Chronicles: The dark brotherhood is the last game in the timeline because this game ends on a cliffhanger ending and will never get a sequel because it reviewed poorly, the developers got bought up by EA, and Sega got sued because of this game.
Sonic the hedgehog 2 is the second game in the timeline because it is the second game
Sonic 3 & Knuckles is the second game in the timeline because is the third game
Sonic CD is the 4th game in the timeline because it introduces Amy Rose and Metal Sonic.
Sonic Advanced is the 5th game in the timeline because it happens before Sonic Advance 2
Sonic Advanced 2 is the 6th game in the timeline because it introduces Cream the Rabbit who has a cameo in Sonic Adventure DX so this game has to happen before Sonic Adventure
Sonic Adventure is the next game in the timeline because it's the next mainline sonic game
Sonic Adventure 2 is the next game in the timeline because it is the next mainline sonic game
Sonic Heroes is the next game in the timeline because it follows up Shadow's death in sonic adventure 2
Shadow the hedgehog is the next game in the timeline because it follows up on heroes plot point of Shadow being a robot
Sonic battle is the next game in the timeline because Shadow is in it and he knows he's not a robot, which was established in Shadow the hedgehog, and it introduces Emerl
Sonic Advanced 3 is the next game in the timeline because one of the antagonists is a robot based on Emerl from Sonic battle
All the Sonic Riders games take place here because they're cannon to the timeline because Sonic Frontiers references them. They're spinoffs and they can basically take place at any time between Shadow the Hedgehog and Frontiers
Sonic 06 is next in the timeline because it is the next mainline entry in the franchise and it introduces silver into the franchise
Both sonic rivals games are next in the timeline because the events of sonic 06 were erased from existence and this reintroduces silver into the timeline
Sonic and the secret rings is next in the timeline because it gets referenced later in Sonic Generations
Sonic Unleashed is next in the timeline because it introduces Orbot into the timeline
Sonic and the black knight is the next game in the timeline because in Sonic Unleashed, there is a dialogue choice where sonic can choose to schedule a date with Amy. At the end of Black Knight, it is revealed that Sonic is telling Amy the events of the game as an explanation for why he missed their date.
Sonic colors is the next game in the timeline because it introduces the wisps and cubot into the timeline
Sonic generations is the next game in the timeline because it directly follows up on what happened to Eggman following his defeat in Sonic colors
Sonic lost worlds is the next game in the timeline because it introduces Zavok into the timeline
Sonic team racing is the next game in the timeline because all of the characters in the game have been added to the timeline now and this game gets referenced in frontiers for some reason so it's cannon
Sonic Mania is the next game in the timeline because it is a prequel to Sonic Forces
Sonic forces is the next game in the timeline because it is the next mainline entry and Zavok is in it so it has to happen after lost worlds
Sonic Frontiers is the next game in the timeline because it is the most recent mainline game in the franchise, references numerous old games, and introduces Sage into the timeline
The Murder of Sonic the Hedgehog is the next game in the timeline because it is the only other game at this time to have Sage in it
Sonic Chronicles: The dark brotherhood is the last game in the timeline because this game ends on a cliffhanger ending and will never get a sequel because it reviewed poorly, the developers got bought up by EA, and Sega got sued because of this game.