The 25 Years of Sonic the Hedgehog

Sonic Generations (2011)

Sonic Generations was released on Sonic's 20th anniversary. It was the year that Sonic turned twenty, five years ago.

The game's plot takes place following the events of Sonic Colors, in which Sonic the Hedgehog defeated Dr. Eggman and sent him out into space. In the past of Green Hill, Classic Sonic was running until he heard a noise. Suddenly, the mysterious entity known as the Time Eater appeared in the sky and the screen washed white.

In the present day, Sonic celebrated his birthday with his friends until the Time Eater disrupted the party, sucking everyone through various "time holes" and scattering them across different points in Sonic's past. Sonic tried to stop the monster, but was easily overwhelmed by its power. After regaining consciousness, Sonic found himself in a strange dimension known as White Space, a realm where time and space ended up after they have been 'erased' by being drained of color and life. Sonic rescued his best friend Miles "Tails" Prower and as they searched for their friends, they encountered versions of themselves from the past, referred to as their "Classic" selves. As the two Tails determined that Time Eater's actions were damaging time and space itself, which was why it was white and lifeless, both "Classic" and "Modern" Sonic raced through their history, restoring time to normal and rescuing their friends. They also realized at one point that the Time Eater's weakness were the chaos emeralds.

After restoring the worlds and collecting all the chaos emeralds, they discovered that the mastermind behind the Time Eater was Eggman and his classic self, who was faking himself to be a victim of the Time Eater all along. He revealed that while drifting through space following the events of Sonic Colors, Eggman discovered the Time Eater, thinking about the idea to use its powers and decided to join forces with his past self to harness its power. Although the Time Eater managed to nearly defeat the two Sonics, the support of their friends and the power of the chaos emeralds allowed them to transform into Super Sonic and confront both versions of Eggman. Despite attacking with missiles, warping arms and slowing down time, the Sonics penetrated the Time Eater's core, destroying it. The heroes returned to the present and continued celebrating Sonic's birthday. After the party, Classic Sonic and Classic Tails traveled back to their own time as everyone bids their farewells.

A post-credits scene showed the two Eggmen lost in White Space. The two argued as they search for an exit, discussed whether or not they ever defeated Sonic and contemplated if they should go back and get their teaching degree as opposed to continuing their misdeeds.