I should make it clear that, for once, I know exactly of what I speak. I have run the Bastard Jedi game three times, and have become quite familiar with how players play it.
For a long time, I've been thinking about how to turn my Bastard Jedi game from an insane tabletop into an insane computer game. I'm sure the guys who tried to make the first D&D computer game had a similar headache.
The biggest issue with the Bastard Jedi game (on the computer it's called "Star Knights" or, in full, "Star Knights: We're Not Jedi, Honest") is that the player's character(s) are not simply a stack of combat statistics. There needs to be a progression through a more... moral... area. That's the point, even in the very dualistic Star Wars games that exist now.
However, these dualistic games that currently exist do it pretty badly. Better than nothing? Maybe, but not as good as I would like.
The real problem is that these games offer you one choice - light side or dark side. Once you've made that choice, you'll typically choose the same way throughout the whole game, meaning that the hundreds of carefully-scripted "choices" that the game pops up aren't choices at all: one option is very dominant and the rest aren't worth thinking about.
This is made worse by their use of points as a primary reward mechanism. Light side vs dark side. You want to get as many points of your given side as possible, because they give you more power and make you look nifty. There are other rewards involved - cash, items, and flavor - but the points are very long-term and personal. It would take a gamebreaking injection of cash, items, or flavor to make you choose against a moderate number of points, so the points are obviously going to be the dominant reward mechanism. Since a specific pattern of secondary awards are usually associated with one kind of points or the other, players will tend to choose one kind of points and be wholly satisfied with both the primary AND secondary reward mechanisms (people saying "thank you" vs people dying in a fire, for example), which further unbalances the system.
It's possible to rebalance these choices such that the points you like oppose the secondary rewards you like. However, with such limited secondary rewards, it is difficult to do this very often without accidentally making the player swap his points preference. IE, he wants the light side secondary rewards, so he chooses dark side points.
There are other measures that can be taken to take care and make it interesting, but the truth is that it's a very limited mechanism and prone to becoming very muddy and not-fun if you make it too balanced.
What we really need are a whole lot more long-term rewards of a whole lot more types. And this is what my Bastard Jedi games were centered around.
Screw light side vs dark side, my Bastard Jedi had six or seven emotional axes, each of which could be considered to be light side or dark side. For example, humility vs arrogance. Having points in either direction gave you advantages if you used that axis and, in turn, using that axis made you more likely to gain another point in it. So your 2 points of humility will give you a +2 if you are humble in combat (or whenever), but it may increase to 3 points of humility.
There is no "OH YOU FELL" moment. No "oh, now you're dark side" moment, nor any "oh, you're redeemed now" moment. Not built into the rules, at any rate.
What there is is a powerful addiction that forms. The pressure of the game is enough that you really want those bonuses, and it's an easy habit to use your traits to get that edge.
Until you start to realize that you're using it all the time, and at more and more severe levels. You can't use two points of humility if your humility is at five, even if you only need two points of bonus.
At two points of humility, you're humble. That's okay. It's a Jedi trait, right? But at five points of humility, you're not humble: you've developed a serious self-worth issue and self-destructive tendencies. This is not because of the rules. This grows organically out of having to role play your use of ever higher levels of humility.
There's the catch, see? You fell without really noticing. You fell to the "light half" of the axis.
As a side note, this also tends to create unstable equilibriums, where players will start to use their less severe emotions to get smaller bonuses and attempt to keep their severe emotions under control. But that increases their less severe emotions and, before too long, you're a wreck.
And it's all done by the player, to the player. There are no rules that say, "oh, you have four emotions above (absolute value 4), you're now an emotional wreck." The rules don't have to say that. It becomes painfully clear to the player.
Quite aside from any other long-term results such as plot events, new saber crystals, and changing relationships with other player characters, these six or seven emotional axes are enough to power the whole engine on their own.
They can't be easily translated to a computer game.
They can be, mechanically speaking. But without the social pressure to make you RP your emotion, there's no real connection between choosing one emotional axis or another. You can program in RP - make the character(s) act appropriately - but now you're taking it away from the player and making it character development by partial fiat. Furthermore, it's very, very difficult to script all the different ways that characters should express their various emotions in various situations!
To be honest, I think the scripting involved would probably be manageable in a AAA title, because I don't see how it could possibly be larger than the scripts for Mass Effect or Fable II. But for one hobbyist, that's a retarded level of scripting to aim for.