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