I think the bigger issue with regard to flat versus fleshed-out characters has less to do with your personal backstory and more to do with inconsistencies between the gameplay and the character's overall attitudes and ethics. Like Justin said, Mass Effect 2 has an early sequence where you get all righteous while putting down looters. Then the game expects (and even rewards) you for going into houses and stealing everything that isn't nailed down.
The same thing happens in the new Deus Ex. Without giving any spoilers, there's a bit at the end where you can make this big impassioned plea that a certain group of people aren't responsible for their evil actions and should therefore be pitied. Then the game puts you in a position to murder dozens upon dozens of those same people. It's a contradiction within the context of the game, regardless of the player's personal outlook.
The same thing happens in the new Deus Ex. Without giving any spoilers, there's a bit at the end where you can make this big impassioned plea that a certain group of people aren't responsible for their evil actions and should therefore be pitied. Then the game puts you in a position to murder dozens upon dozens of those same people. It's a contradiction within the context of the game, regardless of the player's personal outlook.
