Hyper Sonic

I mean come on

Or the Spin Dash in Frontiers if that counts

The majority of them aren’t even worth it. Such as the 100% rewards for Sonic Heroes and Sonic Lost World.

IDK

@BurgerGuyForever

It's so funny that Adventure DX pretty much makes you beat the game as Sonic again once you've beaten all missions, which I did

It's not even 100% completion. You also need to fully finish Mission Mode which I never could because of two IceCap missions. One requires you to make an extremely specific jump at the end, and the other requires you to grab very thin flagpoles. Both are in the snowboarding section

Really? I unlocked Metal Sonic on the Gamecube back in 2017 and it didn't make me finish the missions to do it.