Unless you can hack it, no.
Birdo is not unlockable in Super Mario Galaxy.
You cannot unlock Yoshi in Super Mario Galaxy; he is not in the game. Yoshi will, however, be unlockable in the upcoming sequel, Super Mario Galaxy 2.
Giga bowser is not unlockable in Super Mario Galaxy. That character does not even exist in Super Mario Galaxy.
Wario isn't in the super Mario galaxy series
You can't get the red star in super mario galaxy 2
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.
Yes, Luigi is playable in Super Mario Galaxy. You unlock him after getting all 120 stars as Mario.
the only character that you could unlock by playing super Mario galaxy 1 is rosalina because she was only in super Mario galaxy 1 and now 2
Quite simply, you can't.But, if you've got Super Mario Galaxy 2, you can unlock him after you complete Yoshi Star Galaxy.In short: You can only play with him in Super Mario Galaxy's sequel.Hope that helped.
Bowser is not a playable character.
there red
It does once you unlock Yoshi in Yoshi Star Galaxy.