Score at least 2,000,000 points in any solo mode performance.
Flawlessing moves gives significantly more points than Nice, which gives more points than Almost and a Fail. The multiplier seems to be inconsistent and hidden in this game.
The Gold Flashcard moves earn four times as many points as others so keep an eye out on moves to focus on.
Turning OFF Freestyle Sections will add a new section into the song which also scores points. I'm not sure if keeping on this time will score points as in the last game it didn't.
Finally the Harder difficulties score much more points than lower difficulties.
Make sure to practise!
For curiosity's sake, I got this on "DJ's Got Us Falling In Love".