The backgrounds and backdrops have all gotten an upgrade. The new character models may be off-putting for some at the start, but you definitely get used to them quick and don't even notice anymore. I have played it on every system (including iOS) and have been watching my wife play it now on Steam.
Having grown up playing this game repeatedly on the SNES as Final Fantasy III, I can tell you that here in 2017 that this version of the game is the best you can currently play.
