Brian Drummond the voice of Knuckles in Sonic y su banda (1999) is the voice of Dr. Eggman in the series.
Shadow's trail is yellow for the first time since the character's debut in Sonic Adventure 2 (2001)/Sonic Adventure 2: Battle (2001). The games after that gave Shadow a red orange trail.
The password to Tails' lab is "1992". 1992 was the year Miles "Tails" Prower first appeared in the Sonic The Hedgehog video game series in Sonic the Hedgehog 2 (1992).
In one of the alternative realities, Tails sports 7 mechanical tails beside his two natural ones, making him a nine tailed fox. This is not an arbitrary number: The nine tailed fox comes from Asían mythology. For every hundred years a fox lived, it grew another tail, up to a limit of nine. The longer a creature lived, the more wisdom it gained. "Tails" having nine tails is a physical representation of his genius.
Shannon Chan-Kent who played the Roadhouse Waitress in Sonic: la película (2020) is the voice of Amy Rose in the series.