Dwarf World includes mind-bending features like:
A needs system.
Physically based temperature
Keep your dwarves alive as seasons pass, temperature and resources change and new enemies are discovered.
Your dwarves need food, shelter, water, rest.
Your dwarves will be affected by weather and all sorts of horrible effects and diseases (like chopped limbs).
Favorite dwarven activities include: chopping limbs, cooking, freezing, dying. Make sure they have a cozy fire nearby in winter.