The DOOM v1.2 Manual (C) 1993 id Software, inc. To start DOOM, go to the directory in which you have installed DOOM (the default is DOOM), type DOOM, and press the Enter key. If you have finished installation and setup, you are automatically in this directory. OBJECT OF THE GAME DOOM Welcome to DOOM, a lightning-fast virtual reality adventure where you're the toughest space trooper ever to suck vacuum. Your mission is to shoot your way through a monster-infested holocaust. Living to tell the tale if possible.The gameplay for DOOM is quite simple. This is not a cumbersome adventure game, but an action-oriented slugathon. You don't need the reflexes of a hyperactive eight-year-old to win, either--using your wits is IMPORTANT. To escape DOOM, you need both brains and the killer instinct.