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