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