Here is the full list of all 36 Desperados III achievements.
Earn 90 badges.
Hide 750 bodies.
Complete 5 of the Baron's Challenges.
Kill 200 guards using Cooper's double shot.
Kill 10 small animals in one mission.
Kill all 3 golden chickens.
Kill 31 hidden Mimimi devs.
Finish a mission on "Desperado" difficulty.
Interrupt an important healing procedure.
Jump from a tower into a cart of hay.
Make guards follow Kate for 1,000 meters total.
Return the money to the bank.
Decide the outcome of a duel.
Enjoy some cupcakes during a picnic.
Defeat Frank.
Execute a plan with all five characters.
Kill 75 guards with Bianca.
Take care of DeVitt.
Kill DeVitt.
Kill 75 Long Coats.
Mind control 25 guards with Isabelle.
Kill 15 of the hidden Mimimi devs.
Meet Frank on a boat.
Kill 1,000 guards.
Snipe 50 guards with McCoy.
Find Wayne.
Hide 250 bodies.
Find a patient for the dentist.
Make someone follow your footprints for 25 meters.
Blow up a bridge.
Kill 500 guards.
Kill 6 guards at once using only a single skill.
Kill 50 guards using the environment.
In the first part of the mission, burn 5 guards at once with oil traps.
Kill 5 guards at once with dynamite.
Knock out your father.