I would recommend playing the original version(s) before trying this remake. This would be a better remake if it didn't add so much new mid to it, especially with how the new secret Ending E ruins the great final Ending D from the original game. Not to mention the new main quest and boss take up far too much time in the second half and I got nothing out of it personally. More nitpicky and less critical issues I had personally were how almost every new edit of a song from the original game felt like a downgrade, like it was neutered in some fashion. Or how clean and smoothed out almost every texture and model has become to the point where it loses a lot of the grit and grime the original had.
The core game is mostly the same so if you're the kind of person who doesn't care/won't actually play through the other endings you won't notice most of the new changes.