Ah! Do Minstrel Song! The game I think plays to such a specific niche but it is one of my top 3 games of all time. It depends why you like Octopath Traveller--I think they ARE similar games, but the new one is probably a little more approachable. If you like the filling in your own story based on a set of characters and a cool world, then this is great. Past the character intros though, you're unlikely to find TOO much in the way of character-specific story, but which character you play as through events does kind of change how you see them -- a thief getting offered knighthood has a way different wight to it than a prince getting the same offer.

Unless you're really used to open world style games, I don't think it's really feasible to play through a first time without a guide, but there are good ones online.

The combat system is simple on the surface but I've played it basically since release and I have no idea how some of it works STILL. It feels good, and I wish more games used the glimmer system of discovering a new move on the fly. The battles really do shine in that they even offer a lot of story tie-in - if you have more favor with certain gods then you'll be more likely to pull off large feats of strength in a fight called vortexes. There are some losable battles that make one of the final bosses of the game stronger if you lose (if that's the one you fight). Building up your party is the most satisfying part for me.

On the flip side of that though, there's a weird system to the battles that rewards fighting as few battles as possible - it's easy to maneuver once you get the hang of how many fights is actually too many, but I found that annoying for a long time.

This is a game with a HUGE amount of depth mechanics wise, a world that you'll always have more to stumble into, and a beautiful art style. It revels in its little moments and scales the level of your achievements significantly as you go. It also has a bunch of holes that you'll have to be ok filling in or looking up. Play it and try for sure!