Here is the full list of all 35 Warhammer 40,000: Regicide achievements.
Reach level 10.
Complete 10 secondary objectives.
Complete Act I of the main campaign.
Complete 5 secondary objectives.
Complete 3 secondary objectives.
Complete a secondary objective.
Complete the tutorial.
Complete 20 secondary objectives.
Complete 50 secondary objectives.
Complete Act II of the main campaign.
Complete Act III of the main campaign.
Win 10 online matches as Space Marines against random opponents.
Win 20 online matches as Space Marines against random opponents.
Win 50 online matches as Space Marines against random opponents.
Win 10 online matches as Orks against random opponents.
Win 20 online matches as Orks against random opponents.
Win 50 online matches as Orks against random opponents.
Win 100 online matches against random opponents.
Reach level 20.
Reach level 30.
Reach level 40.
Reach level 50.
Kill 3 enemy pieces in a single turn.
Kill 5 enemy pieces in a single turn.
Perform an En Passant capture in an online match.
Promote a Pawn in an online match.
Earn Tier III Orks
Earn Tier III Space Marines
Earn Tier II Orks
Earn Tier II Space Marines
Capture a Rook with a Pawn in an online match.
Capture a Queen with a Pawn in an online match.
Checkmate an opponent within 10 turns.
Win 20 online matches as Orks against Orks
Win 20 online matches as Space Marine against Space Marine