there is no POSSIBLE way to play as giga bowzer. you can only face him. it is not even possible with a cheating divice.
Well explane this you can play as him with AR(actionreplay)! these codes that I'm going to post in are only for VS. Mode but you also need the P1 (m) code on with the P1 Giga Bowser code on with it!
P1 (m)
73UP-44A5-FV0ZJ
XEUR-98HA-2ET90
MYA0-CUAC-1CUYG
P1 Giga Bowser
G7VQ-ZAT8-YVRHG
XD8R-U8G1-8HP72
Wow..It actually worked..!
Well thanks!
Did you play as him in VS. Mode?