I pretty much love everything about this game. It invented a new art-style, perfected the already good battle system from the Bravely Default series, added path actions and other stuff that made the characters usable outside of battles. It has gorgeous music.
This game is a RPG dream come true. It says a lot, that I rate it above the always top-notch RPGs from Atlus in my list. It is as much fun figuring out the weaknesses to break the defenses and invest all my Boost Points into big attacks after the defenses are down as it is to find out the weaknesses to chain attacks in TMS#FE. Going around the cities and learn everything about it's inhabitants and draw connections between them to form a full picture about this community and more background informations about the quests I do for them, it's just delicious.
It is not simply a throwback in old times, as Octopath Traveler does way more than was possible in the years past. It is different: for Octopath Traveler the developers visited past games and looked what made them great. They took that, build upon it and added as much new technology and techniques they could make without losing what was right about the past games. Many say this is a game that could've been on NES or SNES, but in all actuality it would've blown the minds of players in that era. This is not a nostalgia-trip, it is taking the greatness of the past to a new level.