I played until meeting Veteran in the sewers.
Only thing that felt wrong up to that point, was the sprite of veteran guy. It's unreadable with his back toward camera. Until I talked to him I didn't know what exactly I'm looking at.
I think he should look at the camera, so it's clear that he's human character, and only turn his back to us upon triggering conversation.
Controls work without problems, visuals look cool, music and sfx sounds great, and writing is such that I want learn what is going on with this fucked up setting and talk with NPCs to read what they have to say.
Dunno if I'll continue because I don't like Pokemon combat, but I'm tempted to bite the bullet because everything beside fighting is super.
You said the demo is pretty long, what % of the full game does it cover?