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.
Unlock a new master.
Buy the highest armor upgrade available.
Buy the highest weapon upgrade available.
Reach Level 30 in every character of your group.
Reach Level 30 in a trio.
Unlock the Hunter class.
Reach Level 30 in any character.
Spend 9.001 golds.
Win a battle with 7 monsters.
Earn 9.001 golds.
Unlock the Shaman class.
Unlock the Necromancer class.
Unlock the Knight class.
Reach Level 15 in a specific Spell.
Unlock the Game Developers that made the game.
Unlock the Bard class.
Gather 10 grindstones from veins.
Clear a dungeon.
Reach Level 15 in any character.
Roll 20 in any random roll.
Make the blacksmith dance.
Unlock the Barbarian class.
Gather a grindstone by mining veins.
Use a potion while full health.
Roll 1 in any random roll.
Kill an elite minion.
Reach Level 5 in any character.
Kill a dragon.
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.
Finished the campaign.
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 10 dungeons.
Clear 50 dungeons.