Here's why they are present in Episode II:
* Storyline: Episode II focuses on the return of Metal Sonic and his pursuit of the Chaos Emeralds. The game's plot revolves around Sonic and his friends trying to retrieve the Emeralds before Metal Sonic can use their power for his own evil purposes.
* Gameplay: The Chaos Emeralds are essential for unlocking the game's true ending and accessing the "Super Sonic" transformation. Collecting all seven Emeralds grants Sonic the ability to become Super Sonic, a much more powerful form with increased speed, abilities, and invincibility.
* Series Tradition: The Chaos Emeralds are a staple of the Sonic the Hedgehog universe, appearing in various games and playing a significant role in the overarching narrative.
In Episode II, the red rings represent the Chaos Emeralds, a critical element of the game's story, gameplay, and overall connection to the Sonic series' history.