2/3 of them are references to

Sonic's Concept and is also a Skin in Sonic Superstars Cream's Debut (Though inconsistent looks)

A former 90s rival's (A red capped plumber guy) recent 3D platformer since 2017

Sumin didnt just make some characters But also sandbag (Though bare bones)

Act Music as Rounds? (may not apply to every stage)

(coming some time soon or something.) The 1st Sonic Battle Redux arcade Run: Sonic.

Basically

Valgallah's Cream's "Chao Force" Super

Command is

D,DF,F X+Y

(Not finalized yet but its a resemblance.) I have decided to make it 3 Buttoned. Though the Basic attacks mapped A,B and C buttons will also be mapped to X,Y and Z

Silver (With A Counter move with a cost of Power) and Metal Sonic

Despite being Water (Or Mutated Chao) slime sounds

I'm taking you down like its 1998/1999!

So far. The Super Transformation is far from completion. (Super Sonic Sprites by "TheKnucklesMainG4")