The threequel picks up from Sonic the Hedgehog 2's credit scene introduction of Shadow the Hedgehog, as Sonic, Tails and Knuckles have to form an unlikely alliance with Dr Robotnik to defeat Shadow.

This article heavily spoils the plot of Sonic 3 and its post-credits scene, read at your peril ... Sega Where Sonic the Hedgehog 2 introduced Tails, Sonic CD introduced the blue blur's self ...

Casey: “In one draft of Sonic 2, we actually ... from sidekick Tails to friendly rival Knuckles and anti-hero Shadow. While the latest installment’s post-credits scene already revealed ...

Just like the ending of the first two “Sonic the Hedgehog” movies, the third installment sets up the fourth movie — coming to theaters in 2027 — with a surprise cameo.