Here is the full list of all 23 Tourney achievements.
Repay debt to the steel bank
Inebriate 50 people in a single level
Assign a title to one of your knights
Complete the main campaign with the king alive
Become king at the end of the main campaign
Have every type of outlet in a single level
Earn over 5000 coins in a single level
Buy a knight all of the top tier equipment
Win by more than 10 points in the joust minigame
Successfully complete sharpshooter scenario
Get rid of the beggar in the story of Plip
Score 32 points in archery with a knight that has less than 50% archery skill
Earn over 1000 coins in a single level
Have a knight own each type of potion
Have an entertainer cheer up a knight who was on < 10% happiness
Get a knight to level 10 in the main campaign
Have your knight kill an opposing knight in a joust charge
Successfully complete the story of Plip “wins the day” ending
Successfully complete the story of Plip “saves the day” ending
Exploited a knight’s critical vulnerability
Throw a noble in the stocks
Have 6 stands in a single level
Have 15 decorations in a single level