This mod replaces Fresh with Ocean Palace from Sonic Heroes. It comes with a custom-made chart for all difficulties. The voice samples were taken from the base game and pitch-shifted accordingly.
Ocean Palace makes heavy use of a musical technique known as "Call and Response", in which a musical phrase is played and then repeated or "answered" by another part of the song. If that sounds familiar, it's because Friday Night Funkin' uses this technique for every one of its songs! So, I thought Ocean Palace would be a perfect fit for this game.