video game, Doom III, first-person shooter, dark corridors, Mars base, sci-fi horror, cheat codes, god mode, full health, unlimited ammo, no clipping, reveal map, spawning weapons, armor pickups, demons, monsters, intense action, eerie atmosphere, dynamic shadows, high-resolution textures, advanced physics, interactive environment, close-up, dramatic lighting, HUD display, power-ups, secret rooms, adrenaline rush, survival, combat strategies, quick reflexes, strategic cover, immersive gameplay, heart-pounding soundtrack, suspenseful moments.