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