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