TWRoO on 19 February 2009
Per save file there are 242.... but 121 of those are just the same stars but done with Luigi.
And those extra ones for each character (the 121st) is only unlocked once you have all 120 previous stars for each character.
So you have to get 120 with Mario, then the same 120 with Luigi, then it unlocks a final star to complete with each character.
