I'm almost sure someone else said this before me, but I had little time to read through the previous six pages of replies, but I'll say this anyways.
Personally, I think alot of things rest on circumstancial areas of things. Grand Theft Auto: Vice City - I played it, and the first mission, you have to KILL the pizza delivery boy bcz you're trying to prevent him from spilling some beans on some deal that was crooked to begin with. When I did it, I kinda felt sedistic. I was getting money and I had spent quite a while trying to find my first objective, and when I finally did, I felt really accomplished. I'd never played a game like that before, but it just stirred something that I never knew was there, nor did I want to know that it was there.
On the other hand, I picked up Max Payne. The first one. This is a story of a man who walks into his house after an ordinary day at work as an on-the-field cop/detective, and his house is broken into, and his wife and baby girl are killed in cold blood in his very presence. When you play the game yourself, it is a VERY scary and horrible experience, as it should be. My heart actually sank pretty low. Granted, the man had been pushed over a certain edge, numbing him to the idea of killing a TON of men on his quest for justice and vengeance, and exaggeration seems to have become an art/necessity for video games, but I think the circumstancial area of a game is what the player remembers. In other words, "WHY" do I need to "kill" these people in this game? What's the motive?
Circumstance is what justifies the action. God's reasons for telling Israel to smite entire tribes was certainly justifiable. Capital punishment is justifiable. Flat out murder or genocide for personal gain is NOT justifiable, obviously. I felt actually kind of good killing those men who slaughtered my "wife and only child" in Max Payne. If thugs came into my house and did that...I'm not exactly sure what I might do. I could see myself taking them down if I could, but whether I would actually kill them or not, that would depend on how impulsive I would be.
When I say it's completely circumstancial, I'm not talking saying it only matters to the character in the game. It obviously matters how it reflects on the player above anything. Circumstance is how the player relates. Is there anything there that's justifiable to cause these thought processes to line up with what God wants or calls for, IF this circumstance were true and happening? That's the question people should be asking.
A ruthless faction comes in and invades your territory/country without qualm or querry and wants to conquer? ..Sure. Kill 'em. Psychotic/deranged serial killer? Without question. Knocking someone off regardless of motive or reason, just to put a huge lump sum in your pocket? ..Um..WRONG. Going postal to rack up score just to see how much you can kill/destroy within a certain time frame. WRONG. The game Postal disgusts me.
You get the idea.