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