Here is the full list of all 71 Golden Light achievements.
Kill your Meat Bro in Co-op while having Traitorous Bastard memento.
Complete 500 floors total
Kill 1000 monsters total
Enter the Murder Room on Meat War
Enter the Val Room
Enter the White Room on Meat War
Enter the Torture Room on Meat War
Complete 20 floors without dying
Enter the Field Room on Meat War
Enter the Murder Room on MEATZONE
Kill 500 monsters total
Enter the White Room on MEATZONE
Complete 100 floors total
Throw 500 gold at Son
Enter the Val Room on Meat Zone
Kill Scourge directly
Make 1000 gold
Enter the Torture Room on MEATZONE
Kill Castle directly
Make 500 gold
Kill Maneater directly
Find a multy barrel shotgun
Buy a key from Golden Eye Taker
Complete 50 floors total
Save her
Get every memento and open the final door
Put your hands into the talking toilet
Kill Needles directly
Kill Gut Divers directly
Lose an eye
Make 200 gold
Kill Meall directly
Destroy 50 walls total
Collect Marv, Third Lung and Pulp mementos in one run
Collect Huge Chin and Nose with Teeth mementos in one run
Complete 20 floors total
Meet Rose for the first time
Finish any floor without taking damage
Kill a monster with a Tommygun
Kill an Eyetaker with Meat Spear
Kill a monster with a Vein Whip
Kill a monster with a Shotgun
Buy a key from Pile of Meat
Collect 25 keys total
Ressurect your Meat Bro in Co-op
Make 100 gold
Kill Carre directly
Destroy a wall by eating an item
Complete any floor without using your weapons once
Kill a monster with a Map
Kill She in the flashback
Enter the Field Room on MEATZONE
Kill 100 monsters total
The Gut hates you
Kill anyone with your Huge Chin
Find 3 Golden Meats total
Bring a rose to Val
Eat a fire item
Find your first Golden Meat
Eat a poisoned item
Kill a monster with a Revolver
Complete 5 floors without dying
Die
Kill a monster with a pistol
Read a special note
Kill Eye Taker
Complete 3 floors total
Kill a monster with a Pipe
Burn a monster to death
Complete 1 floor in Co-op
Kill a monster with an Axe