post-apocalyptic setting, underground metro tunnels, dim lighting, gas mask, first-person perspective, abandoned train cars, mutant creatures, survival horror, atmospheric tension, decaying structures, rusted metal, dripping water, eerie shadows, flashlight beam, scavenged weapons, tattered clothing, stealth gameplay, resource management, narrative-driven, Moscow ruins, bleak atmosphere, radioactive fallout, human factions, moral choices, 3/4 view, detailed textures, gritty realism, immersive sound design, dynamic lighting effects, claustrophobic environment.