The Haven Island Add-on for HITMAN 2 has 7 achievements worth 150 gamerscore.
Shoot for gold and look to the sea.
Make like the famous Aussie and leave.
Reach Haven Island Mastery Level 20.
Complete The Last Resort on Master Difficulty.
Complete all Mission Stories for The Last Resort.
Select a Starting Location and use an Informant to smuggle an item onto Haven Island.
Complete The Last Resort.