Discover the secret 'Hades Arm' room

Acquire the Bow of Apollo

Complete story mission 4.

Complete 150 sabotages.

Kill 50 enemies by headshots.

Complete 3 stronghold takeovers.

Destroy 30 objects in 60 seconds.

Complete story mission 1.

Defeat Daedalus; complete the single player Campaign.

Get 30 headshots while scoped in with the Fareye or Marksman in the single player Campaign.

Defeat the Leviathan in the single player Campaign.

Defeat the swarm in the single player Campaign.