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.
Finished the campaign.
Buy all goodies in game.
Unlock all masters.
Visit your Kitchen inside the game.
Kill a dragon.
Visit every single place in game.
Reach Level 30 in any character.
Buy the highest weapon upgrade available.
Unlock the Necromancer class.
Buy the highest armor upgrade available.
Unlock the Shaman class.
Reach Level 30 in every character of your group.
Reach Level 15 in a specific Spell.
Reach Level 30 in a trio.
Unlock a new master.
Continue the game after a game over.
Unlock the Hunter class.
Spend 9.001 golds.
Earn 9.001 golds.
Unlock the Knight class.
Unlock the Bard class.
Unlock the Game Developers that made the game.
Reach Level 15 in any character.
Clear a dungeon.
Unlock the Barbarian class.
Gather 10 grindstones from veins.
Make the blacksmith dance.
Roll 1 in any random roll.
Gather a grindstone by mining veins.
Reach Level 5 in any character.
Win a battle with 7 monsters.
Roll 20 in any random roll.
Kill an elite minion.
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!
Use a potion while full health.
Complete a campaign using all 5 Game Developers as characters.
Play with all classes in game.
Play with all characters in game.
Choose a weird combination of character and class.
Finish the storyline as fast as you can (less than 365 days but you may extend that to 465).
Clear 10 dungeons.
Clear 50 dungeons.