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

Prologue (15 points): Complete Prologue.
Crash Site (15 points): Complete Crash Site.
The Village (15 points): Complete The Village.
Spare Parts (15 points): Complete Spare Parts.
Village Attack (15 points): Complete Village Attack.
Into the Void (30 points): Complete Into the Void.
Prophesied One (15 points): Complete Prophesied One.
The Survivors (15 points): Complete The Survivors.
Prison Escape (15 points): Complete Prison Escape.
Breaking Camp (30 points): Complete Breaking Camp.
Defending the Ark (15 points): Complete Defending the Ark.
The Collector (15 points): Complete The Collector.
The Revolt (15 points): Complete The Revolt.
Tower of Return (30 points): Complete Tower of Return.
Dark Void (100 points): Complete Dark Void.
Ultimate Bad Ass (60 points): Ultimate Bad Ass - Complete Dark Void on Hardcore.
Dear Diary (15 points): Dear Diary - Find a journal.
Bookworm (30 points): Bookworm - Find all journals.
Tesla's Apprentice (15 points): Tesla's Apprentice - Upgrade first weapon.
Grease Monkey (30 points): Grease Monkey - Upgrade all weapons.
Pack Rat (30 points): Pack Rat - Acquire 30,000 Tech Points.
Grand Theft...UFO? (15 points): Grand Theft...UFO? - Hijack 20 UFOs.
Demolition Derby (30 points): Demolition Derby - Collide with another UFO 10 times.
Blind Luck (15 points): Blind Luck - Kill one of each enemy footsoldier using blind fire.
Big Bang (30 points): Big Bang - Destroy a Knight using a grenade.
Captain of the Ship (15 points): Captain of the Ship - Destroy 10 enemy aircraft while yours is on fire.
Forgot My Tow Cable (15 points): Forgot My Tow Cable - Fly through an Archon's legs.
Fireworks (15 points): Fireworks - Kill 10 airborn enemies using grenades.
Get Your Feet Wet (15 points): Get Your Feet Wet - Buzz the water.
99 Red Balloons (15 points): 99 Red Balloons - Kill 10 enemies while they are in an anti-gravity bubble.
Cliffhanger Killer (15 points): Cliffhanger Killer - Kill 50 enemies while in vertical cover.
Death from Above (15 points): Death from Above - Kill 50 enemies while hovering.
Bird of Prey (15 points): Bird of Prey - Kill 25 footsoldiers using your rocket pack guns.
Mark of the Adept (15 points): Mark of the Adept - Destroy 5 UFOs in the Prologue.
Rocket Clothesline (15 points): Rocket Clothesline - Melee an enemy immediately after landing.
Terminal Velocity (15 points): Terminal Velocity - Free fall for 10 seconds.
The Squishy Center (20 points): The Squishy Center - Kill a Sarpa piloting an Archon.
Cleanup on Aisle Three (15 points): Cleanup on Aisle Three - Kill 100 enemies with headshots.
Rochambeau, I Go First (15 points): Rochambeau, I Go First - Kill 50 enemies with melee attacks.
Blue Light Special (15 points): Blue Light Special - Kill 3 enemies with one grenade.
Killing Spree (20 points): Killing Spree - Kill 10 enemies within 60 seconds.
Those Aren't Fortune Cookies (15 points): Those Aren't Fortune Cookies - Step on 10 slugs.
Light Up the Sky (30 points): Light Up the Sky - Destroy 25 targets with the Ark's AA guns.
Master of Arms (15 points): Master of Arms - Kill an enemy with every rifle weapon.
I'm a Rocketman, Baby (15 points): I'm a Rocketman, Baby - Perform 100 special maneuvers with the rocket pack.
The Devastator (30 points): The Devastator - Destroy 25 UFOs while piloting a Survivor fighter.
Float Like a Butterfly (20 points): Float Like a Butterfly - Escape from 10 melee attacks.