i think different animations for different girls would be a really nice change from the first, while the first tl was great the biggest flaw was lack of variety
also maybe some slight altaration to gameplay, so it's not just just sit and wait, maybe a way to attract a girls attention, or something you need to do to keep a hold of some girls (like the most basic example would be mashing space to capture)
just some idea's, i have no idea how you make games so i don't know how plausable some of the idea's are but i hope it's usefull to some degree