Complete the campaign on medium difficulty

Find all the documents.

Find the secret entrance to the Sanctuary.

Destroy the armor of a fully armored enemy, then kill him with a melee attack.

Stab 15 enemies from behind without being noticed.

Complete a level without being damaged.

Kill 4 enemies at once with the Bazooka.

Have XIII drown.

Unlock 15 doors.

Eliminate 6 enemies with one magazine of the Revolver.

Find a way into Emerald Base.

Eliminate 15 enemies with a headshot in one level.

Get full armor.