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