They should've at least remade the UI in HD instead of just applying some xBrz-like filter over the whole thing and calling it a remaster. Prinny 1 and 2 are two of my top favorite PSP games so I hate seeing them treated like this.
You can switch to the menu that you are referring to by going to Settings > Driver > Menu Driver and changing it from ozone to xmb. Then restart retroarch.