You have to complete all the missions, but you don't have to get "A" rank to get the new costumes. He apparently gave her a jewel or letter.
a)ok.this is confusing. once i went to one of 'em cheat websites and once they said that if you finish sa2 with sonic/shadow with or without "A" rankings, you could get alternate costumes in 2 player mode. well i've finished the game. even the "last" stage but i don't see any new costumes. is there anything else i need to do or were those guys just lying? b)after finishing the last stage, in the story, what did sonic give to rouge?thanks.