New research published in the APA journal Emotion shows that people have different responses to killing and dying in first-person shooters. From the abstract of the article by Ravaja et al. (2008): “Instead of joy resulting from victory and success, wounding and killing the opponent may elicit high-arousal negative affect (anxiety), with high Psychoticism scorers experiencing less anxiety than low Psychoticism scorers. Although counterintuitive, the wounding and death of the player’s own character may increase some aspect of positive emotion.”
I have not yet read the original article but it sounds very creative.