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

Possible fang/nack sprite sheet? (And nic the weasle (From the comics)

Yoshi and Birdo cosplaying as Ichigo Momomiya

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

Father and Son love

Basically

Valgallah's Cream's "Chao Force" Super

Command is

D,DF,F X+Y

That Hover Move.

It's like the OG game but less stiff.

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

The 3 Promotional Avatars wearing Rain Boots / Wellies

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