The following article contains spoilers for Sonic the Hedgehog 2.
The Sonic the Hedgehog franchise is about to attain a new level of public popularity, maybe even beyond its 90s heyday. With a blockbuster trilogy of films, a new triple-A game, and a couple of series still on the way, the franchise is about to be one of the biggest names out there.
Sonic the Hedgehog 2 has the questionable benefit of releasing on the immediate heels of the announcement of a full Sonic cinematic universe. The problem with that term and the expectations surrounding it is that the film industry's biggest successes and a few of its biggest failures fall under the same category. Looking at the plot, world-building, and plans for expansion in the Sonic film franchise, it's worth speculating where future projects could take the Blue Blur.
As every fan knows, the cinematic adventures of Sonic the Hedgehog differ from his games, comics, and shows in a number of significant ways. The film's take on SEGA's chosen one is an extraterrestrial being from an unnamed alternate world with mysterious superpowers. Hiding out on Earth with a human family, Sonic tangles with Dr. Robotnik, goofs off all over his new home and learns to be a hero.
The second film introduces Tails, a fan of Sonic who traveled from a different homeworld to help him out, and Knuckles, a member of a rival tribe who hunts Sonic to his home. By the end of the second film, Eggman is defeated, but not confirmed dead, and the classic trio of Sonic, Tails, and Knuckles have become a team to fight for good. The trio rides off into the sunset with plenty of unanswered questions and new worlds to traverse.
Of course, the big thing worth discussing when it comes to the Sonic movies' future direction would be the big reveal midway through the credits. A G.U.N. agent explains to the apparent commander that Dr. Eggman was not found after his seemingly fatal fall in the final battle. Eggman is likely to still be around, not just because he's one of the most central characters in the franchise, but because surviving logically impossible conditions to fight another day is sort of his thing. Though Eggman is likely intended to stick around, Jim Carrey may have other intentions. The studio has made it clear that his absence is the end of the character, they won't recast him. With that in mind, his continued role in the franchise is entirely determined by Carrey. If he returns he'll be joined, and if he doesn't he'll be replaced by a new threat.
Shadow the Hedgehog is here. Sitting in a well-hidden research facility, trapped in a containment chamber, but very much awake. The explosive response from audiences everywhere makes it pretty clear that Shadow is the endgame for this trilogy. He's not the Sonic franchise's answer to Thanos, he's something else entirely. Shadow is one of the most powerful adversaries Sonic has ever faced. He's the leader of the villain team in Sonic Adventure 2, the game that introduced him. He's been a fan-favorite part of the mythos ever since.
Shadow is a morally ambiguous character. Neither the pure good of Sonic nor the pure evil of Eggman. In the context of Sonic media, that almost always means that he'll appear from nowhere with the tone of a final boss, then join Team Sonic for the actual final battle. While it's extremely unlikely that Sonic the Hedgehog 3 will follow the plot of Sonic Adventure 2, elements of it will likely make the transition.
Shadow provides an obvious antagonist for the third film, but what could be waiting in the wings beyond the dark hedgehog. There is a massive pile of potential antagonists from the games, most of whom didn't last more than a single game. Chaos, Infinite, Zavok, Mephisto, and more sit unacknowledged by the franchise beyond the occasional name-drop or visual reference. They are all very unlikely to make it to the big screen.
The one good candidate from the games would be Metal Sonic. That robotic threat is often substantial enough to force enemies to become friends. Eggman makes Metal Sonic in the games, but the films are no stranger to changing the backstory. Either unveiling the project that Eggman has been working on in secret or letting it be the machinations of another force in the plot, Metal Sonic would be the perfect antagonist.
The upcoming spin-off series is perhaps the most mysterious aspect of the ongoing cinematic universe. All that's known is that Idris Elba's Knuckles will be the lead. It could be a prequel about his warrior culture, or it could place him in the traditional guardian role over the Master Emerald. The real oddball pitch would be a Knuckles Chaotix film, but that still feels unlikely. Knuckles is a fairly straightforward character, but he's a massive fan favorite. There are a ton of interesting stories they could tell about this new version of the character.
However the Sonic the Hedgehog film franchise develops, fans will be thrilled to see it grow. Whichever direction it takes, the ongoing adventures of Sonic and friends are destined to be a thrill to fans and newcomers alike.