It is not possible in the first game, but in SSB Melee, you have to do a 100-man melee in in Brawl Subspace Emissary.
you need to unlock a few characters involving Jigglypuff, Falco, and Dr. Mario.
No, you can unlock Fox, Falco, and Wolf, but not Krystal.
first complete 100 man melee then falco will appear
Finish the 100 man melee mode then defeat falco.
Use story mode.
You don't unlock him! If you unlock Sonic and play as him, Super Sonic is his final smash.
you unlock ness, captian falcon, wolf, falco, marth, toon link, jiggilypuff, sonic, solid snake, lucario, falco, Pokemon trainer, mr game and watch, R.O.B., luigi, and gannondorf
unlock dr. mario, luigi, falco, and young ink
You can't.
Sonic was not released for Super Smash Bros Melee and is not unlockable.
super silver and o'aggman is not in sonic smash bros
That game is not available in brawl. By blah head.