Full Gameplay Walkthrough...

Complete the indicated task to unlock the achievement.

Achievement	How to unlock
Bitter Victory	Complete the planet Amara Mors in the campaign.
Chaos Filth	Taunt a Nurgling.
Dauntless	Complete the first chapter in the campaign.
Emperor's wrath delivered	Complete the campaign on Hard difficulty.
Faith and Fury	Complete the campaign as Nyra.
For Ultramar!	Complete the campaign as Malum.
Mission Complete	Complete all other achievements.
No mercy for the traitor	Complete the campaign on Low difficulty.
No rest whilst heresy persists	Complete the campaign on Medium difficulty.
Novoza Cleansed	Complete the planet Novoza in the campaign.
Only in death does duty end	Complete every level in the game.
Pathfinder	Find every Secret in the game.
Production Restored	Complete the planet Erythine or the moon Trephine in the campaign.
Purification Complete	Find every Purity Seal in the game.
Retribution	Complete a daring ambush on a powerful enemy vessel.
Weapon of the Emperor	Complete the campaign on Exterminatus difficulty.