The Himmelstein Add-on for HITMAN 2 has 7 achievements worth 150 gamerscore.
Complete The Last Yardbird in Multiplayer.
Complete all The Last Yardbird Challenges.
Sabotage the wedding.
Get a score above 1,000,000 points on The Last Yardbird.
Complete The Last Yardbird as Silent Assassin.
Eliminate the three main targets with the cannon.
Complete The Last Yardbird in Single Player.