Let's do some math: one major idea behind the Twilight Cage is that it has Year Inside, Hour Outside, to the point where one character mentions only being in the Cage for "a few years", while Knuckles claims this same character hasn't existed in over 4000 years. SO! If by, "a few years", he meant, say, five years, that would mean that 800 years in Sonic's world is equal to one year in the Twilight Cage. We see that by the time Sonic and friends come back from the Cage, Robotnik took over the world, which likely took Robotnik years to do. Thusly, let's say Sonic and friends were in the Twilight Cage for a number of months, perhaps exactly five weeks since Ix wasn't messing around (And getting a bunch of aliens to work together isn't something you can accomplish in one day). That's 35 days which is 28000 days. Divided by 365 is 76.7123288 years. Cream only went to play...
And in this time, Vanilla will have probably died of old age... Feel like recruiting Cream on your next playthrough now?
But then how is Robotnik still looking as young as he always was? For that matter, how is he even alive? Even if he was some sort of Teen Genius, which he's not, almost seventy seven years ought to hit somebody HARD...
Eggman Nega has returned ...
That means the sequel could possible have Silver? Yes...
No indication of how *much* time has passed has been indicated, inside or out. Eggman appears unchanged, and the characters themselves only wonder if they've been gone a few years. All the immortality theories assume that a massive amount of time has passed, but there's no real indication of that. Indeed, it could be that the cast only spent a week or so in the Twilight Cage, given we don't know how long travel between the various locales takes. And the Twilight Cage doesn't appear to have much of a way to indicate "years", so the description is rather of unhelpful.
At one point, Knuckles tells Sonic and the gang that "The Marauders wanted to get rid of him, but Shade wanted to keep him alive." What if the leader had been more ruthless than Shade? Feel like doing the sidequests now...
Eggman's conquering of the world in Sonic Forces arguably makes the cliffhanger scarier. After all, it only took a half a year for Eggman to conquer 99.99% of the world in the game and that's just without Sonic to stop him and Sonic's friends fighting tooth and nail. Also, Eggman nearly executed a plan to kill everyone on the planet except for himself in one fell swoop. In this game, Sonic and many of his friends have been gone for years. How quickly would Eggman have conquered the world with even less opposition to stop him even with the Avatar pulling some serious overtime? And if Eggman was willing to commit murder of a planet-wide scale in one game, who's to say he wouldn't - or already had - pulled it again?
Omega is an optional character who is found in Metropolis, and is only available during Chapter 5. The next chapter, Angel Island falls on Metropolis, destroying it, and Omega is no longer obtainable. What this implies is that this is quite possibly the first time since Sonic Adventure 2 where a main cast member dies. Not only that, but it's completely offscreen, in a brutal way and never brought up by the party. What a way to go.
