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