Can you unlock luigi in super Mario 64?

Unfortunately, you can not play as Bowser in Super Mario 64 N64, or Super Mario 64 DS.

But, you can play as Bowser in Super Smash Bros. Brawl Wii, and in Super Smash Bros. Melee

GAMECUBE. [ CAUTION: SUPER SMASH BROS. BRAWL AND MELEE ARE BOTH RATED T FOR TEENS FOR SOME CRUDE HUMOR, AND CARTOON VIOLENCE]