Game: VR overlay speks , Wii controller projecting a VR light saber.
When the blades pass through each other they loose power and the ability to cut for a while - maybe they recharge faster when moving fast, but only reactivate after a complete swing. They re-power with a throbbing buzz.
When an enemy is cut down, a VR body remains lying where ever the bits fell.
Then the defeated player becomes a force ghost until the next game. A score is displayed above the force ghost showing his wins and losses.
(What about in 25 years when we make real light sabers, will Lucas own the copyright the patent is based on?)
