The idea behind Living Darkness RPG was inspired by several sources, some of which are listed below:
Zork ("You have moved into a dark place. You are likely to be eaten by a Grue")
Call of Cthulu (Psychological trauma as a central game mechanic)
Shadowrun (teched-up mercenaries willing to go where angels fear to tread, if the money is right)
The Chernobyl Dead Zone