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