Collect all 120 stars as Mario, defeat Bowser in the final battle one more time. Once you've done this, wait until after the credits to unlock Luigi as a playable character.
Super Luigi Galaxy isn't a real game but in both Super Mario Galaxy and Super Mario Galaxy 2 you can unlock Luigi and play him.
Get 120 stars with Mario
once you have completed the game as Mario and beaten bowser at least twice go on the menu then press the switch that has the Mario and luigi heads on it and you will become LUIGI
Yes, Luigi is playable in Super Mario Galaxy. You unlock him after getting all 120 stars as Mario.
Mario Luigi (Beat the Game)
Yes, You can play as Luigi in Super Mario Galaxy 1 & 2. In Super Mario Galaxy 1, however, you need to really want him. He'll only be playable after collecting 120 stars with Mario (Double what's needed to beat the game).
The Characters starred in Super Mario Galaxy 2, are the same in Super Mario: Mario Luigi, Peach, Toad, and the other character that will star in the game, Yoshi.
no but u get to see him
(The hey is wrong with you?) No, you cannot kill Luigi in Super Mario galaxy. (He's too precious)
Wario is not in mario galaxy 2 but luigi is.
collect 120 stars with Mario AND Luigi, then go to the trial galaxy rock and go to the backside.
"Super Luigi Galaxy" is not a game you can buy at the store. But, you can buy Super Mario Galaxy and unlock Luigi. To unlock Luigi on Super Mario Galaxy, you need to get all 120 stars. Then, you can play Super Mario Galaxy as Luigi.