The focus of player actions is important. For the most part, morality stands outside of gameplay, and therefore is largely ignored. You don't feel bad about Pac Man eating Ghosts, or Kirby eating his enemies, because this is the gameplay. It's not a moral decision - there is no morality involved.
Morality is really only important when it actually becomes part of the gameplay itself. Notice how all the better ways morality are handled are in games which also feature similar RPG elements about character development and choice? This is because that's what morality is - character development. It's also treated as no different than any other choice - being good or evil within a system is really no different than choosing between weapons and magic in RPG.
This is why the best stuff is reserved for extreme morality - just as extreme sword techniques are reserved for dedicating a lot of time and character development to extreme sword use. It's the same system and the same concept, and for the large part, if there wasn't an incentive to keep focused and get better, players would stop and focus elsewhere, because they've explored all the mechanics of that aspect of the game.
What is interesting is that morality is also most commonly applied outside of games, and ideas like common sense, narrative structure, nobility, and roleplaying can all provoke actions and moral choices that are not rationalised by game mechanics themselves. Take the Sims for example - there is no morality or objective to the Sims in any of the games, yet you look at the gameplay of Sims players, and they are routinely overlaying their own ideals and rules, their own sense of morality, on the game itself. For gamers who go in without ideas, these are boring - there's very few goals to actually go after that the game itself provides an incentive for. But for those players that already know what they want to play, the stories they want to tell, and so forth the Sims is perfect, because it's so open that it's letting them do just that.
All of this is keenly seen in The Sims Medieval, which is unfortunately a very badly designed game. It's tried to combine simulation and strategy, and ended up with the worst of both. This is because it features quite a few mechanical issues, as they've basically enforced everything that is normally provided outside of the game to become part of the core gameplay. It's not optional, or expected, but demanded - and the game penalises you for not bringing your own ideas to the game. There's no incentive for this - in fact, it's very counter-intuitive especially to strategy gamers that would be most likely to otherwise enjoy the limited simulation and more structured objective format. Yet, in discussions these issues are always solved by "roleplaying" and other "metagame" concepts that take place outside of the gameplay mechanics the game itself provides. It's like the Sims does Fable, where things are done for their own sake, rather than because there is any objective or incentive to do so.
This is where morality lies for the most part - Foucault-based power theory argues that we self-govern by imposing our own limits and our own rules based upon what we experience and what we expect. Games have, for the large part, been regarded as models for various aspects of reality - we only apply morality in games we believe to be about morality. Games that don't have morality are often focusing on other things - on other skills and abilities. Like all models, morality doesn't apply when you perform experiments in science, it doesn't apply when you solve an equation in mathematics, and so forth. This is because morality is a variable, and in all models, we reduce the variables to what is relevant. We then get to pick and choose what is relevant - and if morality IS relevant, we would have defined it as such. In games, if morality is not a defined variable, it is not expected to be relevant.
But in society, morality IS constantly relevant, because morality is a big part of a person's identity, since it defines (or is defined by) their perception and intent towards others. Being able to identify this is a very important social survival technique.
If you want to know morality through gaming, use a multi-player game, particularly split-screen or co-op gaming with scores and the option of friendly-fire. Someone who will attack their team mates for extra points or more rupees will most likely do this in real life too. This is not default behaviour because that is the game - that's an actual moral choice. It's backed up by the Theory of Altruism, which makes for some interesting gameplay, and great for letting you know which friends you want watching you back, and which you really don't.
