Last time I play Assassin's Creed:Origin, I have to stop halfway because I'm tired of all those senseless killing. I feel bad and sad for those virtual Roman soldier I've killed, how can that even happened? (P.S. I'm not the only one)

I think part of it is because videogames graphics and animation these day is so realistic(and it will keep getting more real) All the blood and gore and violence and how you kill someone are realistically depicted. Or maybe its objective clashes with my identity and values(I'm not okay running around and killing people in real life, of course)

Note that I can "kill" hundreds of infantry in Dynasty Warrior game (which is much less realistic) and doesn't feel a single thing.

I believe that what you consume, whatever it is, effect you one way or another, despite "researcher" tell you otherwise.