No missable achievements (plus 38 unknown)
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Kill one guard.
Save Azai from the mercenaries.
Perform 25 successful stealth kills.
Distract 25 guards using environmental objects.
Use a dead body to lure another guard and then stealth kill him.
Complete a level without getting detected.
Kill a guard by getting other guards to shoot him.
Throw the body of one guard to terrorize another.
Assassinate Kelly, the mercenary captain.
Perform five different types of stealth kills in one level.
Terrorize 10 guards.
Stealth kill an elite guard after stunning him.
View any of the developer commentaries.
Complete a level without killing any guards.
Terrify a guard with a hanging stealth kill five times.
Escape from the Stronghold.
Get the Undetected bonus 10 times in one level.
Complete a level without killing any guards and without being detected.
Determine your fate.
Stealth kill a guard from inside a dumpster.
Complete Dosan's Tale.
Knock out an enemy again that was revived from being knocked out.
Read one of the history lesson developer commentaries.
Distract 25 guards using your equipment.
Terrify a guard and cause him to stumble to his death.
Within a single Focus, aim and throw three different types of items.
Dispatch two enemies at once using a body infected with Toxic Fungus.
Complete one of the original Mark of the Ninja levels using the Path of Wisdom.
Disable a spotlight using the Dusk Moths.
Complete all of the challenge rooms.
Kill a guard from inside the box.
Earn all three seals in every level.
Earn all of the upgrades.
Earn three stars in every level.
Find all three scrolls in every level.
Stun an elite guard with moths then dispatch him.
Complete the game in New Game Plus.