The Minerva's Den Add-on for BioShock 2 has 8 achievements worth 150 gamerscore.
Reached Rapture Central Computing Operations
Reached Computer Core Access
Escaped Minerva's Den
Wrested control of the Thinker from Reed Wahl
Destroy all 10 Vacuum Bots in Minerva's Den
Got 9999 points in one game of Spitfire
Kill a Lancer Big Daddy
Resolve all the Little Sisters in Minerva's Den