First off, the controls. I think the control scheme from Assassin’s Creed would fit the bill, with slight modifications, mostly concerning combat. There would be three stances: Low, High and Aim. Low stance would be the default stance, where Cairne moves slowly and uses short-range attacks and discreet Force powers. High stance would be a fast stance, mostly used when a situation calls for fast movement. In High Stance, Cairne will use overt Force powers. In Aim stance, Cairne stops and auto-target targets from afar, mostly to use Force powers and deflecting blaster bolts.
Since I wish to bring sense into lightsaber combat, nearly every enemy in the game will be either fully functional or disabled. No hit points. When an enemy is in close range, about five meters, pressing the attack button will cause Cairne to charge with his lightsaber, killing the enemy instantly. Think about the Plasma Sword from the Halo series. In extreme close range Cairne will just slash with his weapon without the charge-effect. This way the player will feel like an invincible warrior monk, instead of a woodcutter.
Whenever an enemy shoots at the player, Cairne will automatically block the blaster bolt or missile or whatever. But every hit will reduce his concentration, which regenerates when not under attack. When his concentration reaches zero, a blaster bolt hits, killing the Jedi. As Cairne takes fire, the edges of the screen will darken/brighten, communicating to the player that he needs to get to cover. I imagine this would look pretty good.
The player would have one button for jumping, one button for lightsaber attacks and two for Force; One button for kinetic powers and another for other powers. Most of these actions would be context-sensitive and would depend on the Stance. On Low stance, the lightsaber attacks would be precise stabs and slashes that would cut limbs and incapacitate enemies. Kinetic Force would be used to disarm enemies by yanking away weapons and knocking them over, and other Force would blind opponents temporarily. On High stance, lightsaber attacks would be wild and flashy, kinetic Force would push back and knock over enemies and other Force would be horror-inducing visages. Aim stance would enable lightsaber tossing, a dangerous maneuver since it leaves the player open, telekinetic object tossing and some other Force power that needs targeting.
So that’s the controls, basically. A mix of Assassin’s Creed and melee of Halo.
As stated, the game has two primary choice axis: The Force alignment and the fate of Saladrin. The choices made to help either the government or the rebels are made simply by fighting alongside either group in randomly generated skirmishes, explained later, and selecting plot-related missions for one of the sides. But the Force alignment is more insiduous. The choice to embrace the Dark Side is not an explicit statement, I believe. No-one just decides to become a Dark Jedi and starts to kill people and be a jerk. The path to the Dark Side is subtle, manifesting in the use of power, bouts of rage and abandonment of consideration and restrain, growing ever greater until the Jedi is beyond the point of return. So instead of giving the player options that give him Light Side Points or Dark Side Points like in the Knights of the Old Republic, we will observe the player’s playing style.
The Jedi avoid unnecessary conflict and try to minimise casualties and damage. They would identify leaders and critical personnel in combat and disable them, demoralising the opposition. They would use the Force only to defend themselves, for using Force to kill a living being is to corrupt and pervert it. To revel in its might and thoughtlessly killing enemy combatants and innocents would be to invite the Dark Side. Therefore, every second the player remains in High stance he gains Dark Side Influence (DSI). He also gains it every time he kills a living enemy, uses High Force powers and uses any Force to kill he gains DSI. Every moment when the player is not in High Stance, he loses it. When the player gains enough, he gains a semi-permanent Dark Side Point, which goes away in time. Every Dark Side Point modifies Cairne in some way. His attack speed and Force effects improve, but he begins to lose his grace, replacing it with barely-contained rage. Eventually he replaces his other Force attacks with iconic Dark Side Powers, like Force Lightning and Force Choke. At some points his default dialogue would also change, from calm and precise, to questioning and emotional, to threatening and self-centered. The effect that I’m after is that in combat and plot-related dialogue, if the player does not wish to slip to the Dark Side he has to be serene. As the enemies tend to have liutenants and commanders, eliminating them would be enough to halt attackers. The player would need to avoid unnecessary combat, use Force sparingly and restrain themselves. Like “real” Jedi. But since over combat is more efficient with High stance and Force use, and one of the themes in the story is the Gray Jedi philosophy of treading the line between light and dark, the player is wordlessly encouraged to push the limits. The trick is that the DSI is not showed to the player, generating an air of uncertaintly. Ideally the player would realise the consecuences of his playing style the first time Cairne strangles someone instead of blinding them, possibly either prompting them to play extra carefully to reduce the Dark Side Points or to embrace his choices fully, surrendering into the darkness.
Next time, world mechanics and mission structure.