This chart is good, fun on normal, but a 19 on Hard is under-representing its difficulty, especially compared to basegame Hard tracks of similar ranking. This is more of a 24 or 22, especially considering the speed sections. (and the hyperspeed section! Really! It's very tricky, the bats are no joke either, even if the patterns are simple.)
The difficulty rating should be changed to more accurately represent it's place on the scale.