Here is the full list of all 20 Founders' Fortune achievements.
Sail off after playing on the hardest difficult with default world settings
Accept a ghost as a new member of the village
Sail off into the sunset and start a NewGame+
Have at least 30 tamed animals at the same time
Befriend the pirates
Annoy the traders until send a raid against you
Successfully demand a tribute or present
Earn over 10,000 coins in a single trade
Equip a villager with armor that has a 17 protection rating or more
Survive a raid without anyone falling unconscious
Have a villager unlock every skill in every profession
Equip a villager with a weapon that does 11 damage or more
Save a villager from bleeding out when they have less than 10% of their health left
Celebrate a child becoming an adult
Increase a villager's mood until they get a motivation boost
Complete a masterpiece
Welcome a child to the village
Have a villager unlock every skill in one profession
Survive your first winter
Equip a villager with an axe