The Special Edition DLC Add-on for Mark of the Ninja has 8 achievements.
Disable a spotlight using the Dusk Moths.
Complete one of the original Mark of the Ninja levels using the Path of Wisdom.
Complete the new Special Edition level.
View any of the developer commentaries.
Stun an elite guard with moths then dispatch him.
Knock out an enemy again that was revived from being knocked out.
Dispatch two enemies at once using a body infected with Toxic Fungus.
Read one of the history lesson developer commentaries.