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