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