I bought the original long ago they are both completely different in terms of style I prefer the 2d art of this one
this one is much easier to progress through all the content because its pretty straight forward and simple keep meeting or finding the girl youre interested in everyday and youll progress its easier to manage your hunger, energy and money (with a bit of common sense)
the original is bigger, longer, and not as straight forward there its a few huge maps to explore, its much harder to manage your stats and progress plus the areas are pretty vague so finding all the content without a guide (i believe there is a guide) will be hard, and even then itll take awhile to progress through since the 3d models are very slow in their animations and you cant skip it the only thing thats better is your chosen girl has enslavement paths and once youve completed their questline they basically take you in and feed you/pay your rent/give you money
I would definitely recommend FemU Zero first its easier to manage everything, its shorter, and you can save at anytime (the original you have to sleep to save, which drains your stats)