Here is the full list of all 41 Warhammer 40,000: Shootas, Blood & Teef achievements.
Defeated Warlord Gutrekka
Killed 100 enemies with grenades
Defeated the Killakan
Killed 100 enemies with melee attacks
Killed 500 Orks
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!
Bought every weapon in the store
Defeated the invictor warsuit
Defeated the Chaplain
Killed 500 Astra Militarum
Killed 1 Space Marine
Killed 5 Tempestus Scions
Defeated the Sentinel
Entered WAAAGH! 100 times
Defeated the Genestealer Duo
Defeated The Patriarch
Consumed 200 squigs
Defeated the Biophagus
Defeated the genestealer
Killed 10 Genestealer Cultists
Killed 10 sewer enemies
Defeated The Bastion of Valor
Defeated the Leman Russ
Killed 1 Commisar
Defeated the Boss Nob
Killed 10 Orks
Killed 10 Astra Militarum
Completed all levels on hard
Didn't consume ammo 1000 times as Flash Git
Used Storm Dash to bash enemies 200 times
Killed 200 enemies by throwing the Beast Snagga spear.
Shocked 200 enemies as the Weird Boy
Meleed an ally 100 times
Found all secrets hidden troughout the game
Killed 20 Commisars
Killed 75 Tempestus Scions
Killed 25 Space Marines
Killed 500 sewer enemies
Killed 500 Genestealer Cultist
Bought every hat in the store
Completed all other achievements