Here is the full list of all 20 Realm of Dread achievements.
Play the guitar in the camp
Encounter the first sign
Acquire the flashlight
Complete Chapter I
Find the secret in the tree house
Complete Chapter II
Take a picture of the entity in Chapter III
Complete Chapter III
Cut the power in Chapter IV
Find the fuel canister in Chapter IV
Complete Chapter IV
Escape the Village
Perform a cleansing ritual and defeat the doctor
Complete Chapter V
Acquire the pistol
Complete Chapter VI
Banish the evil
Complete Chapter VII
Exterminate all rats
Explore all optional locations