Take, Grand Theft Auto IV, for example.
It's the way your character hits every step going up and down the stairs that makes it special—the way his head and shoulders gently move up and down as you walk; the way the illumination from your headlights casts shadows on your surroundings;
It's the way your car's engine catches fire after too many crashes; the way the fire slowly expands from the engine compartment to the rest of the car until it finally explodes and the fire spreads to cars around you.... The way the driver of the car next to yours jumps out of her car with her clothes on fire screaming and flailing her arms; the way she drops and rolls around on the ground for a good minute screaming in a futile attempt to put the flames out until the fire finally goes out and she's left quiet, with nothing but her charred remains on the pavement.
It's the little touches....