The Freedom Cry Add-on for Assassin's Creed IV: Black Flag (Xbox 360) has 6 achievements worth 170 gamerscore.
Freedom Cry - Achieve 100% synchronization
Freedom Cry - Complete all missions.
Disarm the Gouverneur and kill him with the branding iron.
Liberate 500 slaves.
Kill 5 guards at once with a blunderbuss.
Free your first slave.