Here is the full list of all 12 Warhammer 40,000: Sanctus Reach achievements.
Destroy a Shadowsword
Kill a Freeblade
Kill 100 Astra Militarum
Destroy a Lord of Skulls
Kill a Morkanout
Win a sandbox game
Kill 25 units with flame attacks
Kill 100 Space Wolves
Kill 100 Orks
Win a multiplayer game
Kill 100 Chaos units
Win a battle