I had a lot of fun making this, I hope yall enjoy the concept!

This would be a 2D Sonic game, but have tidbits of modern games mixed in.

This would take place during the Inkperial Era, with Exotic Creator as the big-bad of the game.

The plot would involve Sonic heading from planet to planet to reach the head Inkperial Base and take it down.

The first zone would be a location on Sonics home planet, and knowing SEGA it'd probably be Green Hill Zone.

It would start off like any normal Sonic game, with Sonic running through the area, destroying basic badniks and fighting Eggman at the end of the level.

However, after the battle, Eggman retreats as ships fill the skies and begin to assault the ground, changing the area into a fiery and chaotic mess with Inkperial Soldiers invading, and going to battle with Eggmans own forces. At the end of the stage, a boss battle occurs where Exotic Creator shows himself, and begins a 3-way fight between Sonic, Eggman, and himself. Sonic wins the encounter but none of the parties are permanently defeated.

Sonic attempts to use the Chaos Emeralds to go Super and take the down the ships, but Eggsicutioner jumps in and knocks Sonic away before he can transform, giving EC the opportunity to steal the Chaos Emeralds. Sonic gives chase but cannot catch them as the Inkperial ships take off.

Sonic finds Eggman and the two decide to team up in order to stop them from taking over the cosmos, both for their own reasons.

Sonic travels alongside Eggman in a ship to different worlds, where Sonic meets heroes as he goes along. There are a total of 8 worlds Sonic travels to, as well as the Citadel, which functions as this games hub world.

SHAPE CITY ZONE

Shape City is the capital city of the Stickverse, where Sonic runs throughout the city, as Stick machines attack him automatically with the pretense that he is a threat. Eventually Sonic arrives at the castle of the king, Redi, where he has to get past the guards in order to get to the throne room and meet with him so he can explain why he is there. After things are settled, Sonic is given a map of the larger multiverse so he can find his way to the head Inkperial base.

STARRY KINGDOM ZONE

Starry Kingdom is on the planet Andromeda, where Sonic navigates through small towns, thick forests and mountains, with a few Inkperial camps scattered throughout. Sonic takes down the camps and frees the members of small towns that were arrested during an Inkperial raid. Sonic meets Kenshin and Cataclysma as they go to battle with particularly large camp, and assists them in taking the camp down.

After the camp is taken down, Sonic introduces himself to the royal siblings as they thank him for his aid. Meanwhile Eggman mocks their medieval-like civilization.

YOLKY TEMPLE ZONE

Yolky Temple is an ancient Egg temple on Eggyhead's home planet, where Sonic has to speed through the booby-trapped temple to outrun the threats the temple poses. The temple is littered with small Egg-bots with a few magical golems that guard the temple present as well. As Sonic speeds through the temple, Eggman finds himself enamored with the temple, finding amusement in the idea of a race of eggs, but also intrigued by the murals depicting a source of extreme power. The two meet up, and are discovered by Eggyhead.

Eggy is cautious at first but quickly warms up to the two, welcoming them to his home. He is quick to explain the Eggs history to them and how he is one of the last few of his kind. Eggman tries to gather information about the power depicted in the murals to which Eggy naively gushes about before he is stopped by Sonic who understands what Eggman is attempting to do, and they head off.

CORELLAN CHAOS ZONE

Corellan Chaos takes place in a large city that was once was the home of many Coritans, now laid to waste by time. A few Inkperial soldiers are in the city, but they are few and far apart. The reason being that the Inkperial base on the planet is under attack from a certain, especially powerful Coritan warrior. Sonic arrives at the base as it bursts into flames as Thrull assaults it. Sonic directly interferes, saving soldiers Thrull attempts to kill. Thrull becomes angry and attacks Sonic for saving his targets, resulting in a chase.

Sonic is saved by Eggman, who manages to hit Thrull with an extremely powerful laser beam from the ship, knocking him out temporarily. Both the Inkperials as well as Sonic and Eggman escape during the window of time they have.

HAZARDOUS HAVEN ZONE

Hazardous Haven is the Citadel, under siege by Inkperial Forces. Sonic fights and zips through the large city, tearing through Inkperial mechs and bringing down airships. Eggman uses his own mechs to combat the ones the Inkperials use, and works in tandem with UMP to fight off the Inkperial forces. The conflict comes to a head as Eggsicutioner is deployed and begins turning the tide in the Inkperials favor, however Eggman sends out his own prize creation, Metal Sonic to fight Eggsicutioner. The two fight to a standstill, neither of them gaining the advantage until Sonic and Eggman join Metal and work together to overpower the robot and the remaining Inkperial forces, driving them to retreat and take a broken Eggsicutioner with them.

The UMP forces and the people of the city briefly celebrate them for their help, overwhelming Sonic and feeding Eggmans ego extremely before the two depart.

RUINED HOME ZONE

Ruined Home is the broken remains of Collector's home planet, where Sonic runs across the pieces of the shattered planet, it's moon and star both decayed and dying, creating a gloomy atmosphere. Sonic makes his way across the broken world, until he eventually catches glimpse of an opposing blue blur flying in the distance. He catches up and makes himself known to them, before the blue figure reveals themselves to be the Collector.

Collector meets Sonic and Eggman as he catches up with Sonic. He intoduces himself as the hero of the multiverse and reveals that he already knows who they are and that he has detailed files on their identities. He tells the two that they shouldn't just jump into the fight recklessly, but both Sonic and Eggman disagree with him and leave him behind to continue their journey.

INKY DYSTOPIA ZONE

Inky Dystopia takes place in a large Inkversian City, filled to the brim with soldiers and Inkperial propaganda. Sonic shakes off Inkperial forces that attempt to chase him throughout the city, zipping around and evading them by taking advantage of the city's structures. Eggman provides distractions and helps keep the Inkperials off Sonic.

Sonic eventually escapes the city and comes to Yukuna Manor, where many familiar faces can be found. Sonic catches up with the heroes he has met thus far, and is introduced to the ones he hasn't. However, Collector is notably absent. The heroes are having a meeting to prepare for a final push to overthrow the Inkperials, and collectively decide that, in the Collector's stead, Sonic will take charge in their final attack.

However, as they plan to attack, the Exotic Creator is revealed to have come into possession of an extremely powerful gem known as the Warlords Stone, and is going to fuse himself with it to become multitudes more powerful. Despite this, not wanting their efforts to go to waste, and with a little bit of encouragement from Sonic, the heroes charge anyways in an attempt to take him down before he can use it.

FINAL FIGHT ZONE

Final fight is, as the name implies, the final battle against the Inkperial empire, with all the heroes and armies you've encountered on your journey all helping bring down the empire.

Sonic runs into the battle headfirst and charges through anything that tries to stand against him, blasting toward EC to get to him before he can transform. Sonic is under a time limit in this zone, encouraging speed and quick action. Sonic reaches the bases core, where Exotic Creator is located, Exotic Creator, not yet transformed, decides to fight in his current state, believing he can still beat Sonic in his normal form. The two engage in a long final battle, but eventually, Sonic prevails and comes out on top, causing EC to retreat and give up his most important base.

This is not the end of the story however, as this is not how things are meant to be.

If you beat the game this way, after the credits, Exotic Creator will taunt the player, with the Warlord Stone on his chest and the 7 Chaos Emeralds in hand, showing that he has not been truly defeated.

However, there is a way to change this.
Throughout the 7 worlds, in each world a Chaos Emerald can be found in special locations. The way you find the Emeralds varies depending on the world. In Yolky Temple, the location is disclosed through a riddle, in Corellan Chaos, it sits on the very peak of a monument during the chase, and in Ruined Home it sits in plain site among many gems inside Collector's lab, etc.

If you can collect all 7 Chaos Emeralds, something changes.

If you arrive at ECs chamber after the time limit is up, he will transform in front of Sonic, and unleash his power, wiping the floor with him and other heroes as well. With the Emeralds however, Sonic recovers, and unleashes his own power.

DEATH OF AN EMPIRE ZONE

Sonic transforms into Super Sonic, and now with the power to go head to head with Exotic Creators new form, he flies off into the battle.

Sonic battles EC in his War Creator form for a while, but with neither side yielding, the fight becomes a stalemate. That is, until a new presence appears.

Collector finally shows up, and seeing the situation, unleashes the full power of the Crystal of Creation, entering his own transformation.

Collector and Sonic both know that they have to combine their powers in order to beat EC in his War Creator form, so they decide to work together.

With Collector and Sonic teaming up, and with the help of their powered up forms, they fight together and manage to destroy EC and the Warlord Stone permanently, putting an end to the Inkperial Empire once and for all.

Thanks for reading all this!

I had fun making this and getting my autism out. Ask me for any other details you'd be curious about in this hypothetical crossover!

where is zerobot going to be in one of the zones