No.
There is no black block in SM64DS, it only shows in the file selection, and waluigi is not in the game.
You need either Wario, Peach or Toad to unlock him.
you can only unlock him if you use an action replay. but if you don't then your out of luck.
You don't unlock him! If you unlock Sonic and play as him, Super Sonic is his final smash.
in sonic adventure dx you can only unlock metal sonic by collecting 130 sonic emblems.
Yes, you cannot solve the purple prizes, which means you cannot unlock Waluigi.
Super Sonic is Sonic's Final Smash; you cannot unlock him as a real charactor though.
Your question's a bit open-ended. Unlock Sonic for which game, exactly?
You can't (But to unlock Shadow + Amy, you type in 5953131313131313)
you can't
You can only unlock Sonic on SSBB no you can get super sonic shadow and you can get their rel form were their not super