Complete the indicated task to unlock the achievement.

Achievement	How to unlock
A Spoon Full of Sugar	Find the fifth signal.
Boomstick	Obtain the shotgun.
Closure	Finish the game on any difficulty.
Cooking on Gas	Obtain the flamethrower.
Guilty Conscience	Find the fourth signal.
High and Dry	Find the third signal.
Living With Ghosts	Find a record of events.
Logomaniac	Find all written documents.
Masochist	Finish the game on Punished difficulty.
Not for Grown-ups	Find the seventh signal.
Occupational Hazard	Find the second signal.
Quiver Down Your Spine	Craft the Bow and Arrow.
Resident Upheaval	Find the sixth signal.
Reunion	Obtain the Reunion ending.
Riven	Obtain the Riven ending.
State Regulations	Find the first signal.
This Station Is Non-Operational	Find the eighth signal.
Walkie-talkie	Find all lost signals.
Whatever it Takes	Finish the game on Intended difficulty.
Woof	Unknown.