Plot

When Dr. Robotnik returns with a new partner, Knuckles, in search of an emerald that has the power to destroy civilizations, Sonic teams up with his own sidekick, Tails, on a journey across the world to find the emerald first.

After settling in Green Hills, Sonic is ready for more freedom, and Tom and Maddie agree to leave him home while they go on vacation. But, no sooner are they gone, when Dr. Robotnik comes back, this time with a new partner, Knuckles, in search for an emerald that has the power to both build and destroy civilizations. Sonic teams up with his own sidekick, Tails, and together they embark on a journey to find the emerald before it falls into the wrong hands. Being directed by Jeff Fowler, and starring Jim Carrey, James Marsden, and Ben Schwartz.

When the manic Dr Robotnik returns to Earth with a new ally, Knuckles the Echidna. Sonic and his new friend Tails is all that stands in their way. Sonic is back with a boom, this is by far the most entertaining of all video game adaptions in history. It was great to see Jim Carrey reprise his role of Dr Robotnik, he plays the role so well the first time and this time he does it even better. There were so many moments within this piece of cinema that hit me with memories from the video games, I think the director done a fantastic job and he definitely had some Sonic Adventure knowledge. A great family film for all the kids to love and those like me who grew up playing Sonic on the dreamcast/Nintendo, these past couple of years have activated alot of nostalgia among the art of film. Highly Recommend this incredible follow up to the Blue Justice himself. 10/10—BrnzReviews

Getting used to his new life in Green Hills, Sonic The Hedgehog has become the town's speedy protector and all is right with the world: but the dreaded Doctor Robotnik returns to Earth and this time he's pursuing the ultimate power to destroy Sonic once and for all: The Chaos Emeralds. When a mysterious fox named Miles 'Tails' Prower tries finding Sonic, another creature known as Knuckles The Echidna gets caught in the fray over the Chaos Emeralds. The worlds of Green Hills and Mobius converge in Sonic The Hedgehog 2.—Johnny-the-Film-Sentinel-2187

A male blue hedgehog, who has adapted to living on Earth, has new allies and friends when the evil mania male villain returns for revenge. They all have to get along if they want to defeat the villain. They all travel a long way to discover some deep secrets.—RECB3

Eight months after defeating Doctor Robotnik (Jim Carrey) (a mad scientist and Sonic's arch-nemesis who is often referred to as "Eggman", who is now marooned on an isolated planet in space) and being adopted by Tom (James Marsden) (the sheriff of Green Hills, Montana and Sonic's father) and Maddie Wachowski (Tika Sumpter) (Tom's wife and the local veterinarian of Green Hills who is also Sonic's mother) as their son, Sonic the Hedgehog (Ben Schwartz) (An anthropomorphic blue hedgehog who can run at supersonic speeds and cannot swim. He wishes to use his powers for super heroics but disregards the welfare of others in favor of his brash and irresponsible personality) attempts to help the public as a vigilante to little success. He keeps making juvenile mistakes and causing harm to public property and coming in the way of official law enforcement.

Tom advises Sonic to remain patient for the day his powers will be needed (and not use them to destroy things and try to be responsible) before he and Maddie depart for her sister Rachel's (Natasha Rothwell) wedding in Hawaii. Sonic plans to have fun while home alone but is attacked by Robotnik, who has returned with the help of Knuckles the Echidna (Idris Elba) (An anthropomorphic red Echidna warrior with superhuman strength and a strong sense of honor. He is the sole survivor of the Echidna tribe after they were wiped out by the owl tribe). Robotnik had used a Quill from Sonic to devise a distress signal for space. The signal was picked up by Knuckles who arrived on the planet via a portal. Knuckles knew that Sonic was a friend of Longclaw, whose owl tribe attacked and decimated the Echidnas. Knuckles made an alliance with Robotnik to destroy Sonic, if Robotnik helps him find the Master Emerald. Knuckles desires to honor the legacy of his extinct tribe and demands the location of the legendary Master Emerald, an ancient relic that allows its possessor to bend reality to their will.

Sonic is rescued by Miles "Tails" Prower (Colleen O'Shaughnessey) (An anthropomorphic yellow-orange fox who is haunted by memories of his village ostracizing him for his two tails, which allow him to fly), a two-tailed fox who idolizes him and comes to warn him about Knuckles. Sonic says that the Master Emerald is just a bedtime story, but Tails says that Knuckles thinks it is real and will stop at nothing until he finds it.

Sonic convinces Tails to help him find the Master Emerald, while Robotnik reunites with his assistant Stone (Lee Majdoub) and, scheming to steal the emerald, offers to help Knuckles. Sonic and Tails follow clues on a map from Sonic's dead guardian Longclaw (Donna J. Fulks) (An anthropomorphic brown owl and Sonic's late mentor/caregiver who is seen in flashbacks and in a holographic message hidden in Sonic's map. Longclaw's messages says that the Master emerald was hidden on Earth and has the power to turn thoughts into reality) to Siberia, where they find a compass within an old temple. From the legend inside the temple Tails and Sonic learn that eons ago the Echidnas forged the 7 chaos emeralds into the master emerald to create a weapon of unstoppable power. The owls attacked the Echidnas as they knew that such power should not be left in the hands of any one species. The owls hid the Emerald on Earth.

Robotnik and Knuckles track them and pursue Sonic and Tails down a mountain. During an ensuing avalanche, Robotnik and Knuckles steal the compass. Tom rescues Sonic (after Sonic calls from the mountain while Tom was attending the wedding ceremony) and Tails by using a ring to Teleport them to the wedding.

Rachel's fiance Randall (Shemar Moore) and his wedding guests reveal themselves as undercover agents of the Guardian Units of Nations (G.U.N.) and capture Sonic. Randall says that Sonic is an uncontrolled extraterrestrial and cannot be left to his own devices. Tails, Sonic and Tom, are then saved by Maddie and a vengeful Rachel. Robotnik and Knuckles find a large water temple containing the Master Emerald. Sonic goes to the temple and fights Knuckles while Robotnik uses the distraction to seize and fuse himself with the emerald, which explodes and sinks the temple into the water. Sonic and Knuckles escape (after Sonic saves Knuckles from the collapsing columns and the oceans filling in) and agree to work together as Tails rescues them in a biplane.

In Green Hills, Robotnik uses his new abilities to create a giant robot resembling himself. Sonic, Tails, and Knuckles work together to fight the robot and its accompanying drones and to reclaim the Master Emerald, but it breaks, splitting into the seven Chaos Emeralds. Tom and Maddie rescue Sonic, who uses the Chaos Emeralds to transform into Super Sonic. He destroys the robot before dispersing the Emeralds and reverting to normal. Knuckles fixes the Master Emerald from the remaining shards and agrees to guard it with Sonic and Tails. The three resume an idyllic life with the Wachowskis.

In a mid-credits scene, Stone infiltrates G.U.N. as they begin searching for Robotnik in the Mech's rubble. An agent reports to G.U.N. Commander Walters (Tom Butler) that a 50-year-old file containing coordinates to a research facility housing Project Shadow has been uncovered.