Final Fantasy's biggest need is for a GREAT script. For almost two generations now the handheld spinoffs have been better in this regard than the main titles. FF games consistently feel like S-E either rolls with a first draft or reworks the life out of the script.
This is actually XIII's biggest failing. The script had a lot of great ideas, but the execution was terrible because they weren't thought out. Most of the characters work on their own, but put together they just don't connect. Noel's one-line about Snow in XIII-2 that he hates him, but also understands him is a thousand times more meaningful to both those characters than all of the chemistry Light and Snow had in all of XIII.
Music? S-E consistently does that well. XIII suffered because the script wasn't good enough to sell a great soundtrack.
Towns? XV actually looks like it's at least mostly set in a single city. It certainly has been promoted with much more urban content than FF games before now, which tend to be suburban or rural. Depending on how much it's set in the city and how well that city is designed, it may not need towns by classic RPG standards. Even if there are rural sections to the game, it could add a layer of strategy because you can't shop easily out in the boonies, so you need to prepare. It will probably, however, benefit from a day-night cycle so we can enjoy proceedural NPC routines.
Gameplay? XV looks like party based Dissidia meets Shadow of the Collosus. If it meets even half that potential, it will be phenomenal. I actually kinda like XIII's combat system, too (although I can see why people would hate it.)
Just don't make bosses and enemies tough by giving them millions of HP. This does not make for a challenging boss: it makes for an annoying and tedious one, and about the only one in all of XIII who deserved all the health it had was the Long Gui in XIII-2. Because that boss was huge and deserved a ton of HP. Bosses should be tough because they adjust to player strategies at a reasonable rate and fight back in an intelligent manner. Not because the damage they can absorb only makes sense in scientific notation and have super-attacks which bring your whole party down to 1 health.







