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