There are 41 achievements with a total of 1000 points.

Cairo Station (30 GS)
Complete Cairo Station at Normal, Heroic, or Legendary

Outskirts (30 GS)
Complete Outskirts at Normal, Heroic, or Legendary

Metropolis (30 GS)
Complete Metropolis at Normal, Heroic, or Legendary

The Arbiter (30 GS)
Complete The Arbiter at Normal, Heroic, or Legendary

Oracle (30 GS)
Complete The Oracle at Normal, Heroic, or Legendary

Delta Halo (30 GS)
Complete Delta Halo at Normal, Heroic, or Legendary

Regret (30 GS)
Complete Regret at Normal, Heroic, or Legendary

Sacred Icon (30 GS)
Complete Sacred Icon at Normal, Heroic, or Legendary

Quarantine Zone (30 GS)
Complete Quarantine Zone at Normal, Heroic, or Legendary

Gravemind (30 GS)
Complete Gravemind at Normal, Heroic, or Legendary

Uprising (30 GS)
Complete Uprising at Normal, Heroic, or Legendary

High Charity (30 GS)
Complete High Charity at Normal, Heroic, or Legendary

The Great Journey (30 GS)
Complete The Great Journey at Normal, Heroic, or Legendary

Warrior (100 GS)
Complete the game on Normal difficulty

Hero (50 GS)
Complete the game on Heroic difficulty

Legend (50 GS)
Complete the game on Legendary difficulty

King of the Scarab (20 GS)
Acquire the Scarab gun on the Metropolis level, any difficulty

Silent but Deadly (20 GS)
Kill 7 opponents from behind in a row without being spotted, any level, any difficulty

Demon (25 GS)
Complete any campaign level without dying once on Normal, Heroic, or Legendary

Go Ape Shiv (20 GS)
Kill an enraged, berserk Brute by melee, any level, any difficulty

Stick It (5 GS)
Stick an opponent with a plasma grenade and blow them up

Counterpoint (5 GS)
Kill the sword carrier

Carjacking (5 GS)
Steal an occupied vehicle from an opponent and take it over

Violent Cartographer (25 GS)
Play every available default map and stay in each game until it’s over

Rainman (25 GS)
Play every available game variant, with at least 3 other players, to the end of each game

Double Kill (20 GS)
Kill 2 opponents within 4 seconds

Triple Kill (20 GS)
Kill 3 opponents within 4 seconds

Killtacular (20 GS)
Kill 4 opponents within 4 seconds

Killing Spree (20 GS)
Kill 5 opponents in a row in the same game, without dying

Running Riot (20 GS)
Kill 10 opponents in a row in the same game, without dying

Sniper Kill (10 GS)
Kill an opponent with the sniper rifle or the beam rifle

Roadkill (10 GS)
Run over, hit and kill an opponent with a vehicle

Bonecracker (10 GS)
Hit and kill an opponent with a melee attack

Assassin (10 GS)
Melee an opponent from behind

Skewer Stopper  (20 GS)
Kill the sword carrier after they kill 5 or more times in a row with the sword

Vigilante (10 GS)
Stop a Killing Spree of another player

Air Traffic Control (20 GS)
Blow up the Banshee in flight while manned, with grenades or the rocket launcher

Decorated Soldier (10 GS)
Get awarded at least 8 different medals in one non-team game

Ninja (20 GS)
In a non-team game, kill 5 people by melee, from behind

Flaming Ninja (20 GS)
Kill an opponent that has the Ninja achievement

Hired Gun (20 GS)
Kill an opponent who has the Legend achievement

(20 GS)