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

Top Agent (20 points): Bonus for completing the game on Normal difficulty.
Heroic Agent (30 points): Bonus for completing the game on Experienced difficulty.
Legendary Agent (40 points): Bonus for completing the game on Hardcore difficulty.
Gaining a Foothold (10 points): Complete 3 stronghold takeovers
Conqueror of Panau (20 points): Complete 9 stronghold takeovers.
A Trusted Ally (20 points): Complete 49 faction missions.
First Taste of Chaos (10 points): Cause chaos for the first time.
Saboteur (10 points): Complete 150 sabotages.
Destroyer (20 points): Complete 1000 sabotages.
Professional Hitman (20 points): Assassinate 25 colonels.
Up to the Challenge 1 (10 points): Complete 10 challenges.
Up to the Challenge 2 (20 points): Complete 50 challenges.
Leaving No Rock Unturned (25 points): Collect 1000 resource items.
Finders Keepers (15 points): Collect 100 resource items.
Faction Benefactor (20 points): Collect 150 faction items.
Globetrotter (20 points): Discover 100 locations.
Freeroamer 1 (10 points): Reach 100% complete in 15 locations.
Freeroamer 2 (20 points): Reach 100% complete in 100 locations.
Body Count (15 points): Kill 750 enemies.
Unarmed and Dangerous (15 points): Kill 50 enemies using melee attacks.
Gravity is a Bitch! (15 points): Kill 30 enemies by using the grappling hook and making them fall to their death.
Follow Me! (15 points): Kill 5 enemies by dragging them behind a vehicle with the grappling hook.
Hang 'em High! (15 points): Kill 30 enemies while they're suspended in the air with the grappling hook.
Wrecking Ball (15 points): Kill 5 enemies by smashing them with an object tethered to your vehicle with the grappling hook.
Piñata Party (15 points): Kill 5 enemies with the melee attack while they're suspended with the grappling hook.
Juggler (15 points): Kill 30 enemies while they're in mid air.
Road Rage (10 points): Kill 30 enemies by mowing them down with vehicles.
Marksman (15 points): Kill 50 enemies with head shots.
Killing Frenzy (20 points): Kill 20 enemies in 60 seconds.
Invincible Warrior (20 points): Kill 50 enemies in a row with inventory weapons without losing health.
Destruction Frenzy (10 points): Destroy 30 objects in 60 seconds.
Test Driver (10 points): Drive 30 different vehicles.
Trying Everything Once (25 points): Drive all 104 vehicles.
Road Trip (20 points): Travel 75 kilometers by land vehicle.
Please Step Out of the Vehicle (10 points): Hijack 50 enemy vehicles.
Stunt Driver (10 points): Get 100 stunt driver points.
Halfway there (25 points): Reach 50% completion in the normal mode or mercenary mode.
Parachute Climber (10 points): Open the parachute and then land on foot 300 meters above the starting height.
I Believe I Can Fly (10 points): Base jump 1000 meters.
Bridge Limbo (20 points): Fly an airplane under 30 unique bridges in Panau.
Stunt Flyer (10 points): Fly an airplane close to the ground for 30 seconds.
Perfectionist (25 points): Reach 75% completion in the normal mode or mercenary mode.
Top of the World (10 points): Stand on foot on the highest point of Panau.

Additionally, there are seven secret achievements:

Welcome to Panau (10 points): Complete Story Mission 1.
Casino Bust (20 points): Complete Story Mission 2.
The White Tiger (30 points): Complete Story Mission 3.
Mountain Rescue (40 points): Complete Story Mission 4.
Three Kings (50 points): Complete Story Mission 5.
Into the Den (60 points): Complete Story Mission 6.
A Just Cause (70 points): Complete Story Mission 7.