Here is the full list of all 23 Foreign Legion: Buckets of Blood achievements.
Kill 1337 enemies in total
Kill 5 enemies with an air raid
Kill 2500 chickens
Reach level 20
Survive 30 minutes in endless mode
Purchase the Foreign Legion FAMAS
Play a game with only the Night Vision Goggles equipped
Find the minigun
Kill 4 enemies with one rocket
Kill all enemy waves in 7 minutes
Beat the Village in the extreme difficulty
Repair the town hall 5 times in one round
Play a game with only the Smiley Badge equipped
Play a game with only the Peace Badge and Bullets equipped
Finish the campaign on any difficulty
Destroy the supreme chicken overlord
Purchase an outfit, helmet and accessory
Escort the bus safely without it taking damage
Win the game with all civilians alive
Kill 25 chickens
Make a kill chain of 10 kills
Make 15 headshots in one round
Kill all chickens in one round