Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Prologue (10 points): Complete Chapter 1.
Exposure (10 points): Complete Chapter 2.
Baggage Claim (10 points): Complete Chapter 3.
Moths To The Flame (10 points): Complete Chapter 4.
The Shipment (10 points): Complete Chapter 5.
The Bait (10 points): Complete Chapter 6.
Industrial Evolution (10 points): Complete Chapter 7.
Unnatural History (10 points): Complete Chapter 8.
Threshold Guardian (10 points): Complete Chapter 9.
The Dark Sector (100 points): Complete the Game.
Dark Sector - Brutal Difficulty (110 points): Complete the Game on Brutal Difficulty.
Headhunter (10 points): Decapitate 30 Enemies.
Incinerator (10 points): Incinerate 30 Enemies.
Electrician (10 points): Electrocute 30 Enemies.
Jack Frost (10 points): Kill 30 Frozen Enemies.
Finesse (40 points): Kill 30 enemies with Aftertouch.
Hardball (35 points): Kill 30 enemies with Power-throw.
Sharpshooter (10 points): Get 30 Headshots.
Glaive Master (10 points): Complete a Level by Only Using the Glaive.
The Finisher (10 points): Perform 30 Finishers.
Double Decap Latte (15 points): Get Two Decapitations In One Shot.
Skeet Shooter (10 points): Shoot 10 Projectiles in Mid-flight.
Weaponsmith (10 points): Apply 5 Upgrades in the Black Market.
Greed (10 points): Collect over 50,000 rubles.
Researcher (10 points): Collect 10 Weapon Upgrades.
Master Researcher (15 points): Collect All the Weapon Upgrades.
Rebound (15 points): Kill an Enemy With a Reflected Projectile.
Glory (30 points): Finish Best Overall in a Ranked Infection Match (Multiplayer).
Veteran (30 points): Score 500 Points in Ranked Infection Games (Multiplayer).
Hero (40 points): Score 2000 Points in Ranked Infection Games (Multiplayer).
Champion (30 points): Finish Best Overall in a Ranked Epidemic Match (Multiplayer).
Comrade (30 points): Score 500 Points in Ranked Epidemic Games (Multiplayer).
Hero of the People (40 points): Score 2000 Points in Ranked Epidemic Games (Multiplayer).

Additionally, there are five secret achievements:

Colossus (50 points): Defeated the Colossus.
Stalker (65 points): Defeated the Stalker.
Nemesis (85 points): Defeated the Nemesis.
Ghost (35 points): Used Shifting to get a finisher.
Jack the Jackal (35 points): Took the Jackal for a ride.