Here is the full list of all 41 Warhammer 40,000: Shootas, Blood & Teef achievements.
Bought every hat in the store
Completed all other achievements
Found all secrets hidden troughout the game
Killed 75 Tempestus Scions
Killed 500 sewer enemies
Killed 20 Commisars
Used Storm Dash to bash enemies 200 times
Killed 100 enemies with grenades
Killed 25 Space Marines
Meleed an ally 100 times
Bought every weapon in the store
Killed 100 enemies with melee attacks
Shocked 200 enemies as the Weird Boy
Killed 500 Astra Militarum
Defeated Warlord Gutrekka
Defeated the Killakan
Defeated Lord Horrik Canorem, Son of High King Valorik Canorem, High Prince of House Canorem, Master of the Blade of Gaia, Keeper of the Gates of Loralo, Wielder of the Kaloric Flame, Bringer of Hope, Herald of the Holy Order of the Adamantine Lance, The Paladin of Koto, Slayer of the Lion of Essa, The Triumphant! The Light of Stars! The Eradicator!
Defeated the invictor warsuit
Defeated the Chaplain
Killed 5 Tempestus Scions
Killed 1 Space Marine
Completed all levels on hard
Defeated the Sentinel
Entered WAAAGH! 100 times
Killed 500 Genestealer Cultist
Consumed 200 squigs
Killed 1 Commisar
Killed 500 Orks
Killed 200 enemies by throwing the Beast Snagga spear.
Defeated the Genestealer Duo
Defeated The Patriarch
Defeated the Biophagus
Defeated the genestealer
Killed 10 Genestealer Cultists
Killed 10 sewer enemies
Defeated The Bastion of Valor
Didn't consume ammo 1000 times as Flash Git
Defeated the Leman Russ
Defeated the Boss Nob
Killed 10 Astra Militarum
Killed 10 Orks