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