This document provides a concept overview for a tactical action/interactive film called "CATARSYS: Last Face of Armageddon". The story follows a man during an alien invasion of a small industrial town. Throughout the 24 hour gameplay, the player makes choices that influence the hero's behaviors and determine how the story ultimately ends. The goal is to use mathematical algorithms rather than scripts to generate unique, individual endings based on the player's own logic and psychological responses to the unfolding events.