What are ratings? What does “Flawless Victory” mean?
At the end of the song, you’ll get a rating for your performance in the song. The rating is based on the percentage of balls you hit, the percentage of streams you followed (if any), and the percentage of obstacles you managed to avoid. This will yield one of 10 possible ratings between F and A++.
The top rating of A++ corresponds to a “Flawless Victory”, and can only be attained if each ball was hit with full strength, no streams were missed, and no obstacles were hit.