Here is the full list of all 12 Dark Lord Demo achievements.
Get a conflict between your advisors
Learn how to manage your manor
Make 100 choices
Flog somebody 10 times
Meet the Merchant
Now the Manor belongs to the Cat
Conquer your first kingdom!
Upgrade the Cat's influence level to 10
Delicious cupcake and not poisoned at all
Discuss your health with one of the advisors
Yes, you definitely need a zombie wyvern. Totally safe!
Why did you drink all these potions?