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