Here is the full list of all 42 Knights of Pen and Paper +1 achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Complete a campaign using all 5 Game Developers as characters.
Finished the campaign.
Reach Level 30 in every character of your group.
Unlock a new master.
We know it may be frustrating to die so we've just rewarded you with this achievement. Do not give up, the game is about to begin!
Gather 10 grindstones from veins.
Clear a dungeon.
Spend 9.001 golds.
Reach Level 30 in any character.
Visit every single place in game.
Reach Level 15 in a specific Spell.
Unlock the Necromancer class.
Earn 9.001 golds.
Gather a grindstone by mining veins.
Unlock the Shaman class.
Reach Level 30 in a trio.
Unlock the Bard class.
Unlock the Knight class.
Unlock the Hunter class.
Win a battle with 7 monsters.
Reach Level 15 in any character.
Unlock the Barbarian class.
Make the blacksmith dance.
Unlock the Game Developers that made the game.
Roll 20 in any random roll.
Roll 1 in any random roll.
Use a potion while full health.
Reach Level 5 in any character.
Kill an elite minion.
Kill a dragon.
Continue the game after a game over.
Play with all classes in game.
Play with all characters in game.
Visit your Kitchen inside the game.
Buy the highest weapon upgrade available.
Buy the highest armor upgrade available.
Choose a weird combination of character and class.
Unlock all masters.
Finish the storyline as fast as you can (less than 365 days but you may extend that to 465).
Buy all goodies in game.
Clear 10 dungeons.
Clear 50 dungeons.