Yoshi and Birdo cosplaying as Ichigo Momomiya

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

(Advance 1) Angel Island Zone.

Originally for Infinite Battle Now retooled

Early previews of "Shining Wine (Not alcohol)" and "Castle Party"

Akin to MUGENhunter's Tails

Every Continue and Confirming

As of 6/26/2022

Despite being Water (Or Mutated Chao) slime sounds

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

The "Big Green Man" (Guest) teaser.

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