The Ranger Pack Add-on for Metro 2033 has 9 achievements worth 240 gamerscore.
Complete the game in Ranger Mode Easy.
Complete the game in Ranger Mode Hardcore.
Kill 50 enemies with heavy automatic shotgun.
Kill at least one enemy with each weapon available in the game.
Get 50 kills with Volt Driver.
Get 25 kills with alternative fire of Volt Driver.
Kill 30 humans with only pneumatic weapons.
Kill 50 mutants with your knife.
Kill 15 enemies using sticky grenade.