I am not sure if any of this already have been suggested, but I will go on anyways:
- Automatic Sliding Doors
- Human NPC's (which may be both friendly or hostile)
- NPC Villages (which may be both friendly or hostile)
- Hunting Bow and eventually other ranged weapons
In case NPC's would become a thing, it'd be cool if they could populate your own city at random if sufficient amount of houses is available. And if there even could be events of rebellions or hostile NPC's blending in with the other NPCs.