The Siberia Add-on for HITMAN 2 has 7 achievements worth 150 gamerscore.
Complete all Crime and Punishment Challenges.
Complete Crime and Punishment in Multiplayer.
Make Roman Khabko kill Vitaly Reznikov and subsequently try to run away on his own.
Get a score above 1,000,000 points on Crime and Punishment.
Complete Crime and Punishment as Silent Assassin.
Summon assistance by shooting locker 137.
Complete Crime and Punishment in Single Player.