So I made this Ultimate Timeline Form of the games from 1991 to 2018

I made these images, which are quite long, but they fit everything (I think). It would be very confusing to write the timelines here, so I made the images.
https://imgur.com/a/qEEo6JY
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Here's the deal. I tried to establish clear criteria to define what is canon and what is not. A game is not canon if:

• It is a misrepresentation. This is when a game portrays characters in a completely different way than they should be, playing unthinkable roles. Example: Waku Waku Sonic Patrol Car (1991).
• It is a puzzle/educational game. These are games made to teach mathematical operations, tile matching, etc., very common in the 1990s. Example: Sonic's Schoolhouse (1996).
• It is a crossover. This is when characters of the Sonic franchise team up with characters of other franchises in a game. Example: Mario & Sonic at the London 2012 Olympic Games (2011).
• It does not have a plot. It is not possible to consider that the plot of a game is part of the canon if the game has no plot at all. Example: Sonic Drift (1994).
• It belongs to another universe. Although it is a game that may possess all the characteristics of a canonical game, it is set in a separate universe. Thus, it can be canonical for that universe, but not for the main one. Example: Sonic Boom: Rise of Lyric (2014).

Additionally, the following condition has been added to consider that a game does not belong in the canon. A game is not canon either if:

• It was not originally released for console or PC. Several games were released for mobile, arcade or electronic toys and, if they were relevant to the canon, they should have been released for console right away. Example: Sonic Jump (2012).

The only exception is SegaSonic the Hedgehog (1993), referenced in the Sonic Mania Plus (2018) booklet, which says that when Might and Ray last saw Sonic they were escaping from Eggman Island.

At the same time, a game can be "canon" and be part of a timeline that no longer exists. The most famous case is Sonic the Hedgehog (2006). Sonic Chronicles: The Dark Brotherhood (2008) might be the case as well.

I know that Sonic Team makes games with Infinite inconsistencies and Forces us to accept them. But I focused on a list of alleged inconsistencies in order to be able to make these timelines. Here they are:

• There are three sequels for Sonic the Hedgehog 3 & Knuckles (1994), all involving Metal Sonic. In Sonic the Hedgehog 4: Episode Metal (2012), Metal Sonic has remained unconscious on Little Planet since his defeat in Sonic the Hedgehog CD (1993). In Sonic Mania (2017), Eggman finds Metal Sonic's location on Little Planet during the battle in Press Garden. In Knuckles' Chaotix (1995), Eggman had to recover Metal Sonic's CPU, as his body had been destroyed.
• After Sonic in Sonic Generations (2011) asked Tails if Green Hill looked familiar, Tails said "not to me". This is a reference to the fact that Tails has never been in Green Hill, since he did not participate in the events of Sonic the Hedgehog (1991). However, in Sonic Mania (2017) he goes to Green Hill. Not only that; all Master System / Game Gear games in which Tails participates in the events are all located on South Island and it is difficult not to know Green Hill in this case.
• In Sonic the Hedgehog 2 (8-bit) (1992), Sonic and Tails are already friends and live on South Island, when Tails is kidnapped by Eggman. But Sonic only met Tails in Sonic the Hedgehog 2 (16-bit) (1992) on West Side Island and there is no time for this adventure to take place before the end of Sonic the Hedghog 3 & Knuckles (1994) – what would make this game a fourth sequel to Sonic the Hedghog 3 & Knuckles (1994).
• In Sonic the Hedgehog 4: Episode Metal (2012), Metal Sonic was rescued in the bad future of Stardust Speedway. It was to be expected that Sonic had managed to make the good future. The same bad future can be seen in Sonic Generations (2011), although in this case perhaps it was the influence of the Time Eater.
• In Sonic Generations (2011), Sonic from the Classic Era was seen as the past of Sonic from the Modern Era. However, in Sonic Forces (2017) he is seen as a Sonic from another dimension.
• In Knuckles' Chaotix (1995), Vector, Espio and Charmy were captured by Dr. Eggman. In Sonic Heroes (2003), Charmy has never heard of Dr. Eggman.
• In Sonic Rush (2005), Eggman Nega is seen as Eggman's counterpart in Sol Dimension and they are allies. In Sonic Rivals (2006), Eggman Nega is a descendant of Eggman in the distant future and is his enemy. In Sonic Rush Adventure (2007), they are allies again. In Sonic Rivals 2 (2007) they are enemies again.
• After Silver changes the events in Sonic Rivals 2 (2007), he says in Sonic Colors (DS) (2010) that his future is good and happy. But in Sonic Forces (2017), Silver had to travel to the present to warn about his chaotic future. And Sonic Chronicles: The Dark Brotherhood (2008) is another game in which Eggman has apparently conquered the world. On the other hand, in Sonic Generations (2011) Modern Eggman claims that he never managed to defeat Sonic, and in Sonic Rivals (2006) Eggman Nega came from the future stating that Eggman disgraced the lineage because of his failures.
• In Sonic Rush (2005), Sonic and Blaze met. In Sonic the Hedgehog (2006), Sonic and Blaze met again as if it were the first time and Blaze lived in Silver's future.

Spoiler

 

As the whole idea of the Adventure Era and Modern Era stem from the bad future of Sonic CD can make people cringe, it is possible to make an alternative version of the Classic Era in which the good future is the most important.

Spoiler

 

I didn't include Sonic the Fighters because it fell under the criteria of not being released for the console in its release. I know that it was going to be ported, but since it wasn't, I exclude it.

I couldn't explain how Tails designs a rocket that requires 8 Chaos Emeralds anyway. And it's strange that the new characters are already treated as friends of Sonic and protectors of the Chaos Emeralds, but we've never seen them before.

 

Well, I disagree. Even if classic games imply that there is a set of Chaos Emeralds on each island, it is easily acceptable that it was retconned and that it was actually the same set all the time. As far as I can remember, the only controversy this could cause is in the Sonic 3 manual, but you can work around it. People finding Chaos Emeralds more easily is just a matter of script.

We always assume that Sonic got the good ending in each game because he is the hero and such, but Sonic CD is the only game in which we saw the bad future being applied to another game (Sonic 4). In no other game did this happen. It is very difficult to come up with an explanation for the bad future shown in Sonic 4 that never happened. And speculating what would happen as a result of this bad future should be the work of Sonic Team, the timelines are only used to try to organize the games.

Regarding the 8-bit games, I kind of agree, but since Sonic from Sonic Mania and Sonic Forces is confirmed to be the same Sonic from Sonic Generations, it needs to be the 16-bit Sonic.

 

We all do, I think. We all do.

The problem with considering only the main games is the presence of characters like Blaze, Silver and Cream. There may be some other problem, but this is what I'm remembering now.

 

And Sonic Battle, because of G-merl in Sonic Advance 3.

Shuffle, the Riders series and those of mythical books are really unimportant. But these are just 5 games, we can shove them in the timelines somehow haha

 

It is actually possible to make a timeline in which Metal Sonic only appears after the bad future, and kind of easy. Take the original timeline of this post and just place Knuckles Chaotix, Sonic 3D Blast and Sonic R after Sonic Mania Plus. It's like a mix of the two timelines that I posted.

In that case, absolutely no game exists after Sonic 3K in the good future.

 

I found it quite similar to mine. The main difference is the moment when Classic Sonic and Classic Tails were taken to Generations, and from then on in the classic timeline.

But one thing made me curious: why would Sonic Rush Adventure come after Sonic Unleashed?