Here is the full list of all 24 Princess.Loot.Pixel.Again achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Make a party!
Collect 46 artifacts
Necromancer saves King
Berserk saves King
Get Rank C
Paladin saves King
Make four deals with the cat in one run
Rogue saves King
Collect 15 artifacts in one run
Collect 23 artifacts
Archer saves King
Collect 3000G in one run
Candlevania!
Mage saves King
Find baby
Explode the door
Press TAB in the main menu
Warrior saves King
Get Rank S
Find hidden place
Die for the first time
Get Rank A
Get Rank B
Start main Quest