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

Late night shopping (10 points): "Awakening" level is complete.
Jogging (10 points): "Run from Beast" level is complete.
Subway (10 points): "Kurskaya Station" level is complete.
Ruins (10 points): "Inside the Perimeter" level is complete.
Back to back (10 points): "Field Hospital" level is complete.
Ominous silence (10 points): "Way to the Base" level is complete.
Heart of evil (10 points): "The Mound" level is complete.
Home sweet home (10 points): "The Base" level is complete.
Showdown (50 points): "Final Battle" level is complete.
X-files (25 points): All secret cocoons have been collected.
Snoop (25 points): All gene cocoons have been collected.
Collector (15 points): All close combat weapon has been collected.
Humanitarian (25 points): You did not kill a single soldier when you were running away from the Beast.
Suicide (25 points): The Beast has been killed by its own shot, reflected from the shield.
Immortal (50 points): You have completed all levels without a single death.
Anonymous Alcoholic (25 points): You have broken 50 bottles.
Explosives expert (15 points): You have blown up 20 barrels.
Sportsman (25 points): You have jumped 100 times.
Master of reflection (25 points): You have reflected 200 shots with your shield.
Butcher (25 points): You have killed 5 enemies in one 'rage' spell.
Blood bath (50 points): You have killed 8 enemies in one 'rage' spell.
Overmind (25 points): You have taken 30 aliens under control.
Cat's eye (20 points): You have spent 15 minutes in Alien-view mode.
Illusionist (15 points): You have killed an enemy with shots reflected from the shield.
Biologist (20 points): You have collected gene material of every alien type.
Kick-boxer (25 points): You have kicked to death 20 kamikaze.
Grendier (15 points): You have killed 2 enemies with one grenade.
Senior Grenadier (25 points): You have killed 3 enemies with one grenade.
Ripper (25 points): You have killed the Terminator with a grenade.
Prybar master (25 points): You have killed 100 enemies with close combat weapon.
Sharp-shooter (50 points): You have killed 100 enemies with distant combat weapon.
Moscow saviour (10 points): You have killed 100 enemies.
Planet saviour (25 points): You have killed 250 enemies.
Galaxy saviour (50 points): You have killed 500 enemies.
Vivisectionist (25 points): You have dealt fatality to 10 aliens.
Fatalist (50 points): You have dealt fatality to 25 aliens.
Post graduate (10 points): You have achieved maximum level in one of the skills.
Bachelor (50 points): You have reached maximum level in all of your skills.

Additionally, there are three secret achievements:

Energy blast (25 points): The Annihilator has been killed by a grenade explosion.
Deadly metal (25 points): The Beast has been killed by a grenade explosion.
Alien DNA (25 points): You disconnected a monster from the Swarm and it killed the Beast.