Can't AAA Excite Bike

[chemicalrabbit]

I tried so many times. I've done it before at the library without sound, but with sound on the song confuses me and I get goods instead of perfects. I play Stepmania and just starting playing FFR yesterday; FFR is different from Stepmania.

Can anyone tell me the differences between the two? I'd like to know so I can see what I'm doing wrong.. I seem to have no problem with other songs in FFR above Very Challenging, but Excite Bike is just an usual stepfile for me.