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