Today I completed the first character's chapter 4 after ~45 hours. The credits rolled, but there are obviously still seven other characters left, plus who knows if the game continues into one ultimate path once all eight storylines have been finished.
Anyway, Octopath Traveler doesn't do much to expand its combat system. I've said it in some thread last week that subclasses on the way to chapter 2 are the only addition. The subclass menu uses a ring to assign classes and there's still some empty space, so I assume that the game should have master classes, but I didn't get anything after finishing chapter 4 with one character, so who knows...
Another thing I mentioned is the level design which is the same across the board. Walking and fighting is the only thing you do. No changes through chapter 4.
What's evident is that Cyrus is the best character to choose as your main; the main character gets locked into your party until you've completed their fourth chapter, so the initial choice you make at the very start of the game matters quite a lot. I didn't pick Cyrus, but I strongly recommend to pick him. His unique talent is a free Analyse on all foes at the start of each battle, so enemies' weaknesses are much easier to figure out. His class also contains the skill that allows you to split the enemy encounter rate into half which is very handy anytime you go through low-level territory. The difficulty of the game adjusts depending on the number of recruited party members, but it tops out at threat level 11 in the beginning areas, so recruiting the second half of the eight characters is bound to see you fight weak enemies in droves.
Cyrus's combat abilities cover staff (very weak physical attack) and fire/ice/thunder elements that hit all enemies, even twice with unlocked skills. Makes him the best magic caster in the game when it comes to taking care of regular battles. It's no disadvantage to start with him because all beginning areas have foes that are weak to exactly what you have; but since Ophilia is another staff user with light and healing magic, I'd recommend to proceed clockwise at least for your second party member. Choosing Cyrus as your main gives you a versatile and useful character that you'll gladly keep in your party until the lock is lifted after completing his chapter 4.
Whereas Bravely Default was dreadful after 30 hours, I still want to play Octopath Traveler after 45 hours. A few of my characters have passed level 50, so they are technically overleveled (chapter 4 recommendation is 45), but the bosses have so much HP in this game that my party doesn't feel overleveled. I run a rather basic skill setup where I emphasize MP conservation and additional turns. It reminds me very much of the job system in Final Fantasy games where there are lots of useless skills and only a few of them really matter.
Routine sets in rather quickly in Octopath Traveler, but the EXP gains remain solid until you hit level 60 and the writing of the characters is interesting enough to be motivating. There are certainly better RPGs out there, but this isn't a stinker like Bravely Default. The most annoying things in Octopath Traveler are to figure out what enemies are weak against and the rather high random encounter rate, but both of those things can be mitigated by having Cyrus in your party. Right now I'd give Octopath Traveler a 7/10 which is a good score on my review scale. I can't see it getting higher because of the lack of variety in its gameplay; whether it will go lower will depend on how the game truly ends. I am not sure if a possible encore after all chapter 4s are cleared would be a good or a bad thing. This is already a very long game, after all.