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 15 artifacts in one run
Collect 46 artifacts
Find baby
Berserk saves King
Press TAB in the main menu
Necromancer saves King
Warrior saves King
Archer saves King
Mage saves King
Get Rank S
Rogue saves King
Paladin saves King
Collect 23 artifacts
Candlevania!
Collect 3000G in one run
Get Rank C
Make four deals with the cat in one run
Find hidden place
Get Rank A
Get Rank B
Explode the door
Die for the first time
Start main Quest