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