You can't unless you use cheats or hacks.
Please, if you can read, then you can understand that it is just a demo.
There are no cheats in Super Smash Bros. Brawl, only walkthroughs.
There are no cheats in it...
There are no cheats for Super Smash Bros Melee.
i wish there are no cheats
only with hacks
TRUTH there is no cheats that was to unlock supersonic !
There are no cheats for Super Smash Brothers Melee. There are un-lockable stages and characters.
No, you cannot play as any boss from Brawl.Don't be fooled by those who claim that there are cheats/hacks to play as them.
There are no cheats, but there are many, many unlockables. Look at: http://www.gamefaqs.com/gamecube/516492-super-smash-bros-melee/cheats for a full list.
unless you use hacks, no.