Here is the full list of all 71 Skellboy Refractured achievements.
Completed the Cursed set
Completed the Midas set
Use the Blazemace to travel into a grim future
Defeated Squaruman, his Skeleton Dragon and even Dark Skippy for the third time, phew!
Opened the gate blocking off the graveyard
Loosened the chain in the torture chamber
Completed The Pumpkin Set
Completed the Dead Beet set
Loosened the chain in the library
Rescued half of all lost Cubolds
Tip over 3 statues
Tip over 4 Cows
Loosened the chain in the windmill
Discover the random dungeon
Completed the Hell Knight set
Entered the Save Grave for the first time
Defeated the Orc gang in the arena
Clear the path for the Granddice to return to the castle
Rescued one lost Cubold
Defeated Croc Ambush in the kitchen
Rescued Sir Ortiz, Knight of the Fourquires
You pulled the axe from the stump
Survived Squaruman's elevator pitch
Rescued Granddice Fluffybeard and brought him back to the Barracks
Defeated your nemesis in the ball room
Rescued Sir Loyd, Messenger of the Foursquires
Defeated your nemesis in the catacombs
Duped the knights to let you into the safe house
Defeated the monster in the swamp
Completed the Zombold set
Beat Captain Lobsclaus
Rescued all lost Cubolds
Rescued Lady Trevora, Keeper of the Foursquires
Rescued Lady Piz, Wise of the Foursquires
Hatch yourself a sun dragon!
Beat Refractured Mode
Collected all hats
Collected all weapons
Found all Save Graves
Completed the Mushroom set
Completed the Knight set
Completed the Crow set
Completed the Chimera set
Completed the Foursquire Set
Completed the Ghost set
Completed the Golem set
Completed the Gourmet set
Completed the Princess set
Completed the Scarecrow set
Completed the Biker set
Completed the Driftwood set
Completed the Doctor set
Completed the Dragon set
Collected all unique items in the Submarine
Zombolds dropped 100 pieces of Zombold bodyparts
Turned 25 enemies into walking cake
Defeated 20 enemies with the Hell Knight's Hellmet
Turned 20 enemies into meat
Collect 50 Emeralds
Collect 150 Emeralds
Collect 350 Emeralds
Buy every item from Matjes at least one time
Collect 100 Coins
Talk to 10 Dead Beets
Bonefire Lit
Have the maximum amount of life and shield cubes
Stack a Medusa on top of a Medusa on top of a Medusa
Wear two helmets at once
Defeat every boss while wearing the Zombold set
Defeat the final boss while wearing the Dark Skippy set
Defeat the final boss while wearing the Princess set