Okay, so this is a game I really like and feel is underappreciated by the adventure game community.
1) In the course of his investigation, the divorced main character teams up with a female police detective. The nature of their relationship varies slightly depending on choices made by the player - it may be purely professional, somewhat romantic or a little hostile. This subtly influences the ending.
2) As general principle, the player can shoot or arrest any character he encounters, although such action ends the game in most cases.
3) At one point in the game, the main character faces two men identifying themselves as NSA agents. He can either engage in a firefight with them or escape into the woods.