Here is the full list of all 12 Dance! It's your stage. trophies - there are 9 bronze, 2 silver and 1 gold.
Finished the first season successfully
Finished the second season successfully
Trained each song at least once
Changed outfit at least 10 times
Made a nice combo of moves in a row
Made a super combo of moves in a row
Finished any song without mistakes
Played a co-op match
Played a face off match
Both players finished a song in co-op without mistakes
Finished Career Mode
Got a gold medal for every song in Career Mode