It's possible to play as GB. Just enter the debug menu AR code(can't remember the site, ask around) and pick him. You can also play as the hands. And sandbag. But he's useless.
I don't use Action Replay. It is
First of all, I would like to point the following out:
I DONT CHEAT!
Hey, genius. Look at the site URL. "Cheathappens". This is a cheat site. Sorry. Feel free to leave.
As for this Giga Bowser thing,
Yes, it is possible using Action Replay to play as Giga Bowser, Sandbag, the hands, etc. This is not a lie.
Here is the site that has the necessary AR codes:
arcentral.net/ssbm/SSBM.html
If you have an AR and you follow all the directions on this site, you can indeed play as Giga Bowser and the rest.
If you do not have an Action Replay, it is NOT possible to play as the aforementioned characters.
Towtha is right! AR can mess up your gamecube and your game. That's why it is