Sudden demo end is sudden. I think the dwarves should have a little bit more autonomy, maybe an ability to place a flag and they would automatically gravitate towards mining towards it micromanaging being for rushing some particular path.
I think one resource for everything is a bit weird, giving no insentive than to dig straight down. Maybe more dense rock nonvaluable rock around points of interest and bigger rewards compared to just dirt would make path- building more engaging.
But a great game so far- just needs more love.