Here is the full list of all 38 Hard West 2 achievements.
Finished the game on the Normal difficulty.
Finished the game on the Nightmare difficulty.
Completed all world map side objectives in Chapter 3.
Visited every location in all Chapters.
Completed all world map side objectives in Chapter 1.
Collected every card in the game.
Finished the game on the Nightmare+ difficulty.
Maxed out loyalty with Lazarus.
Maxed out loyalty with Laughing Deer.
Maxed out loyalty with Old Man Bill.
Killed 60 Hellspawns.
Finish "One Last Ride" in no more than 12 rounds with all objectives completed.
Finished the game on the Hard difficulty.
Finished the game on the Easy difficulty.
Form sets of Royal Flush with 4 posse at the same time.
Form sets of Full House with 4 posse at the same time.
Killed 666 enemies.
Form sets of Straight with 4 posse at the same time.
Finish "The Great Train Heist" in no more than 10 turns with all objectives completed.
Maxed out loyalty with Clalish.
Finish "Wanted: Lady Shrike" in no more than 15 turns with all objectives completed.
Finish "A Plague Upon This Land" in no more than 12 rounds with all objectives completed.
Finish "3:10 To Heaven" in no more than 1 round with all objectives completed.
Finish "Riftwalkers" in no more than 10 turns with all objectives completed.
Maxed out loyalty with Flynn.
Completed a mission using only Shotguns.
Killed 80 Revenants.
Killed 50 Shadow Dancers.
Completed a mission using only Melee weapons.
Finish "O'Kane Farm" in no more than 8 turns with all objectives completed.
Killed 100 Bandits.
Finish "Flynn's Vision" in no more than 10 turns with all objectives completed.
Completed a mission using only Rifles.
Finish "Frostbitten in Calla Calla" in no more than 10 turns with all objectives completed.
Finish "Blasting Out" in no more than 8 turns with all objectives completed.
Completed a mission using only Handguns.
Finish "Fooling The Hangman" in no more than 4 turns with all objectives completed.
Finish "Daredevils" in no more than 8 turns with all objectives completed.