Requirements for opening Challenges:

Blindness - Open from the beginning of the game You can play it in the Pre-Update Version

Sonic Speed - Open from the beginning of the game You can play it in the Pre-Update Version

Hi, I'm Speedy! - Open from the beginning of the game

Rise STYLE - Normal Mode and Legacy Mode are required to unlock it

Ringless - Normal Mode are required to unlock it

og knuckles STYLE - Pussy Mode, Normal Mode and HARDMODE are required to unlock it You can play it in the Pre-Update Version

Handsome Miles's Bet - For unlocking requires completion of all previous Challenges

Requirements for opening "Final of Universe R ACT 1 Demo"

IMPOSSIBLE - For unlocking requires you to complete the game 98% of completion (Pussy Mode, Normal Mode, HARDMODE, LEGACY MODE and all Challenges)