The use of attenuations to balance the resulting mix is one of the best contributors to a natural sounding game. Simple things like extending the maximum distance while changing the curve depth or shape can have a tremendous effect, allowing the sounds to be heard from greater distance at a lesser volume. Alternatively, reducing the maximum distance can help to clean up an overactive mix and gain some clarity between elements.
Additionally, the auxiliary send volumes of an attenuation are directly related to the amount of signal sent to both game and user-defined busses. Ensuring the correct balance between the output bus volume and the game/user-defined send volumes for a sound or group of sounds can help reveal detail and definition in the mix.