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