"One of the first things you’ll notice when playing, is that all of the game’s mechanics are visual cues on-screen. Eschewing the need to take up precious screen space with HUD for the tired light and sound meters, taking focus away from the main screen. New Game+ removes these visual cues for a highly challenging experience. There are also elements of the HUD that can be turned off in the options menu.
Sounds like footsteps, glass breaking, shots being fired and weapons thrown and hitting their target emit a Doppler effect. It is represented visually by an expanding ring to let you know how far that sound traveled and if anyone was alerted to the source. Your character is a ninja, so sticking to the shadows helps your cause. Doing so will bask you in darkness and your character will be in all black save for the red face and white outline. When you step into light, your character is illuminated clearly and shows that you are wearing red and dark blue. This signals when you can be seen and when you can’t."