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