Here is the full list of all 33 Metrocide achievements.
Finish the game on Impossible difficulty
Finish the game on Tough difficulty
Unlock every weapon and tool
Complete a level with all guns and ammo in your posession
10 Innocents were killed by bullets meant for you.
Complete Hilldale
Complete a level killing only gang members
Blow yourself up
Complete a contract by having the mark's own bodyguard shoot them
Complete 20 contracts in a single game
Complete a level without missing a single shot from your weapon(s)
Complete a level without a single body being found
Get a kill with an explosive
Complete The Docks
Complete a level without buying any weapons or kit
Kill 30 gang members
Get a kill with a rifle
Complete a level without failing a single contract
Kill 5 innocents in one game
Get killed by a police drone while carrying a corpse
Complete Downtown
Have a civilian kill your mark for you
Drown a corpse
Get killed by your mark
Escape on foot from a cop drone which is trying to shoot you
Get a kill with a shotgun
Get a kill while strafing
An innocent was killed by a bullet which was meant for you.
Kill a witness to one of your hits
Fail a mission because your target has left the area
Have a cop kill your mark for you
Get killed by a police drone
Die without getting a single kill