Another spy-related theme is stealth. Cate is encouraged to be as stealthy as possible throughout the game although in most missions brute force is also an option. Sound plays a key role in being stealthy. Enemies are able to hear and find Cate if she is walking or running on hard substances. Crouching and/or walking on softer ground enables Cate to move undetected. The game's soundtrack works to let you know whether or not guards are aware of your presence. Slower, relaxed music means she is safe whereas faster, ominous music means she's been detected. Being stealthy has definite advantages. In addition to being able to deal with enemies quickly (and non-lethally, if desired), Cate is able to listen in on the conversations of her enemies. NPC conversations are one of the highlights of the game. Enemy henchmen will discuss the tedium of their lives, cars, philosophy, TV shows, etc. At the end of each level, Cate's performance is scored and ranked, with a large portion of the score coming from how stealthy she was.