So playing more and having visited every major area and town and cleared about 3 of the larger maps, the one thing that's actually disappointing to me is the lack of interaction with NPCs. Not that I would want a huge storyline or tons of branching quests in a game like this, but even basic banter is missing in most cases; with 'place holder' like responses from those who even have the option to talk to them.
In Monsoon, one NPC (who can train you, which is why he even has a dialog option) says "the old jade quarry is empty and monsters have moved in, but I bet you can find some valuable stuff still" and that's it. That's perfectly fine, for a single NPC, but not fine for what is basically 15% of all NPC interactions that aren't trading in that area.
I think just having more lines like that spread throughout, maybe some that cycle local gossip, would work wondrously. Not all NPCs would need it, but just pressing interact with them should give at least a spoken line or some kind of interaction. Many NPCs walk around with stuff in their hands, looking like they're doing something, why not add more life?
Off the top of my head, things that matter in a game like this could easily be communicated with NPC lines.
For example -- did you know that in the swamp area you can feed the fireflies to the large flowers that then produce firefly powder -- which is not only pricey, but a neat example of environmental interaction? An NPC in town, perhaps the alchemist or one near him, could say something like "Those fireflies sure are helpful at night, makes me feel bad when I feed them to the large flowers..." -- it gives a hint of something you can do without spelling it out tutorial tip style.
Or maybe something like "Careful of that foul water -- it's not just muck, there's something vile about it. It poisons things if you linger too long... and that poison doesn't seem very natural." -- this not only gives a hint that the rancid water will poison you if you stay in it a few seconds but also hints at the setting/lore of the corruption and the plague doctor's role.
There's just so much potential in a game like this, and I hope they capitalize on it _hard_.
Similarly, putting more neutral/friendly NPCs around the game world to give it a greater sense of life. It's great you can run into the nomad trader, but why not have some camps of neutral people? Maybe the bandit clans are warring? Maybe you meet some prospectors who need protection? None of this requires any immense scripting, just plop them down and have them give you a quest the way all other NPCs do.
Also, I was very disappointed the paladin dude from the ley line didn't recognize me in Monsoon. I thought we were bros man =(