The game has very good story, good characters, very good soundtracks and there are so many features that makes insteresting to play, BUT you'll have to grind well if you want to be strong enough to not suffer from hard parts of the game.
its early game is a bit hard until Jade becames your party member and after that it becames literally "Jade game", thats because she deals so massive damage and there's no reason to not use her as primary party member. Hopefully at late game other characters deals same damage as her if builded correctly and you wont be able to be braindead that point.
So, about the new things it added to the base game is
Voice Actors, orchestra version of soundtracks, some "filler stories" at mid game, possibility to change between 3D game and 2D game, new mounts, new outfits, some QoL like calling horses and forging anywhere (and now you can buy some material during forge) and new dg that you can challenge secret boss.