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

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

Basically

Valgallah's Cream's "Chao Force" Super

Command is

D,DF,F X+Y

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

The "Big Green Man" (Guest) teaser.

That Hover Move.

It's like the OG game but less stiff.

Despite being Water (Or Mutated Chao) slime sounds

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

(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

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