Here is the full list of all 12 Warhammer 40,000: Kill Team achievements.
Complete a mission in co-op mode
Get over 50 kills with each weapon type
Earn a gold Aquila in every survival challenge
Play through each mission with two different Space Marines
Find all the collectables
Defeat the Warboss!
Unlock all weapons and ability upgrades
Kill 5000 enemies in total
Complete a mission without using melee
Achieve a "Bloodbath" Kill streak
Use a special move
Complete a mission without dying