Here is the full list of all 29 Rustler achievements.
The base game contains 28 achievements, and there is 1 DLC pack containing 1 achievements.
Complete 100% of the game, including all quests, side activities, and obtaining every other achievement.
Complete 100% of the game without dying nor getting caught even once.
Catch all horses for This Neigh Land.
Kill 500 people.
Kill 5 NPC in 5 seconds.
Gain and then remove a maximum Wanted rating without dying and with no quest active.
Use Pimp-A-Horse 20 times.
Collect 20 bodies during the body collecting side activity.
Complete all quests for the Spanish Inquisition.
Come first in 10 races.
Herd a total of 50 NPCs to mass during the church herding side activity.
Collect 20000 gold pieces.
Win 10 fights in the MMA side activity.
Complete the main story line.
Wield all weapons available in the game at least once.
Complete all quests for the Herbalist and the Doctor.
Complete all quests for Salazar.
Kill an NPC with a cow.
Collect all horseshoes.
Survive for 5 minutes at maximum Wanted rating.
Complete all quests for the Priest.
Complete all quests for the Loan Shark.
Collect 5000 gold pieces.
Plow the fields 10 times.
Complete all quests for the Knights of the Holy Grail.
Block 10 attacks in 60 seconds.
Complete the first quest.
Set the amount of blood particles in settings to x5.
Successfully complete the Halloween event.