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