It's weird to get used to, but you don't need to ADS to hit your target and headshots aren't necessary. As long as your cursor (flashlight) is on them, you'll hit. ADS strengthens your light, but drains your battery FAST.

when aiming at enemies, the circle that appears is their shield; they can't be hurt when it's 'on'. shining the light damages the shield. when the shield is gone, thee whole body flickers white, meaning they can be hurt.

Those who are lost in the dark are Taken instead, becoming literal shadows of themselves. The most Common Taken were once hunters, campers or lumberjacks before being turned. Wielding Axes and throwing knives and hatchets.

Assault Taken: these man-mountains are huge, and are shrouded thick darkness. In life, they were laborers and timber workers, and so wield heavy duty weapons such as axes and sledge hammers. less affect by flashlights.

Fun Fact: the original concept for Alan Wake was an open world game with a day/night cycle about a cult in the woods of a small town. They canceled the idea for a more episodic level design in favor of story telling.