Here is the full list of all 34 Sekiro: Shadows Die Twice - there are GOTY Edition achievements worth 1,000 gamerscore.
All achievements have been unlocked.
Attained the "Shura" ending
Defeated "Isshin Ashina"
Defeated all bosses
Acquired all skills
Attained the "Immortal Severance" ending
Attained the "Purification" ending
Upgraded all Prosthetic Tools to their limit
Defeated "Great Shinobi - Owl" at the Hirata Estate
Upgraded Vitality and Posture to their limit
Used Lapis Lazuli to upgrade any tool to its limit
Attained the "Return" ending
Defeated "Sword Saint Isshin Ashina"
Acquired all Ninjutsu Techniques
Used the Mortal Blade to sever the Guardian Ape's undying
Defeated the "Great Colored Carp".
Fully upgraded the "Healing Gourd"
Defeated the "Demon of Hatred"
Defeated the "Divine Dragon" and obtained the "Divine Dragon's Tears"
Defeated the "Corrupted Monk"
Traveled to all areas of the game
Acquired all Prosthetic Tools
Defeated "Great Shinobi - Owl"
Defeated the "Guardian Ape"
Defeated the "Great Serpent".
Caught the Folding Screen Monkeys
Grasped the inner mysteries of any combat style
Defeated "Genichiro Ashina"
Defeated "Lady Butterfly"
Defeated "Gyoubu Masataka Oniwa"
Encountered the Memorial Mob
Returned from the dead using "Resurrection" for the first time
Acquired the Shinobi Prosthetic
Received the "Kusabimaru" from Kuro