I always end up the opposite way...
I try to play a villain.... oddly start feeling guilty, and then play a good guy.
Of course i've always been overly anthromorphic when it comes to videogame characters. Often when playing a game with many characters/teams if i botch something for one character or team i feel the need to start over to "make it up to them" or do something else to do so, despite the fact that it's just one team i'm playing.