Warning: Contains SPOILERS for Sonic the Hedgehog 3!Sonic the Hedgehog 3 includes two post-credits scenes that are pivotal for the franchise’s future, as they introduce major new characters and confirm the fate of another. The final act of the third live-action Sonic the Hedgehog movie is the biggest of the series, as Sonic, Knuckles, and Tails attempt to stop Shadow, Dr. Robotnik, and Gerald Robotnik from destroying the Earth. Sides flip once Shadow and Dr. Robotnik turn on Gerald and work to save humanity, even if it puts their own lives at risk. That makes Sonic the Hedgehog 3‘s ending very action-packed before Team Sonic’s happy ending.

https://screenrant.com/sonic-the-hedgehog-3-post-credits-scenes-explained/