Sonic 2 is a 2021 2.5D platformer/action title on the Cyclone Derecho. It is a continuation of Sonic on the Cyclone Tempest, and is the exact same title as Sonic 2 on the Cyclone Derecho with a few changes to the levels.
Dr. Eggman wants to gather the 7 Chaos Emeralds to power his Ion Cannon superweapon to destroy Central City and cripple the planet's government so the Eggman Empire can take over. Sonic the Hedgehog and Miles "Tails" Prower both go on a mission to stop him from firing the cannon and taking over the world.
Sonic and Tails find the first Chaos Emerald in Cerulean Heights, basically Green Hill Zone with the green replaced by a bright sky blue color.
Crazy Engine Zone
A mechanical zone full of pistons and gears Here lies the second Chaos Emerald.
Electric Paradise Zone
This zone just bristles with electric energy. Sonic and Tails find the third Chaos Emerald here.
Rusty Park Zone
Sonic and Tails move on to Rusty Park, an amusement park once under construction by Eggman Enterprises as part of an evil scheme that has since been abandoned. They find their next emerald here.
Red Grove Zone
The fifth Chaos Emerald can be found in this zone filled with strange red vegetation.
Marble Trouble Zone
In this Marble Zone clone lies the 6th emerald
Egg Shuttle Zone
Sonic and Tails sneak onto Eggman's newest vessel to end his plan.
It this 1-act stage, Sonic and Tails follow Eggman, who unveils his latest creation, Mechhog, to take the 6 Chaos Emeralds from them, already in posession of 1. After trashing him, they move on to the final battle.
Sonic and Tails go to destroy the Ion Cannon, and face off against Eggman one more time in their super forms.