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.
Collect 20 bodies during the body collecting side activity.
Kill 500 people.
Use Pimp-A-Horse 20 times.
Collect all horseshoes.
Herd a total of 50 NPCs to mass during the church herding side activity.
Block 10 attacks in 60 seconds.
Plow the fields 10 times.
Gain and then remove a maximum Wanted rating without dying and with no quest active.
Survive for 5 minutes at maximum Wanted rating.
Kill 5 NPC in 5 seconds.
Complete the main story line.
Wield all weapons available in the game at least once.
Complete all quests for Salazar.
Complete all quests for the Herbalist and the Doctor.
Complete all quests for the Spanish Inquisition.
Come first in 10 races.
Collect 20000 gold pieces.
Win 10 fights in the MMA side activity.
Collect 5000 gold pieces.
Kill an NPC with a cow.
Complete all quests for the Priest.
Complete all quests for the Knights of the Holy Grail.
Complete all quests for the Loan Shark.
Set the amount of blood particles in settings to x5.
Complete the first quest.
Successfully complete the Halloween event.