Er. Terrible demo. Where do I begin?
First, I do love the original Tron video game. Great fun, brings back fond memories, and it would be something I would love to pick up and play more of.
Sadly the current XBLA version doesn't seem like it will be worth a purchase. The most damning design choice: Somehow they decided to have the right thumbstick emulate the original dial control for aiming. It simply doesn't work. I felt stupid, incompetent, and unable to direct my shots where I intended them. Why they didn't just emulate the dual stick control of Robotron, I have no idea. Yes, changing the control scheme would have meant rebalancing difficulty levels -- but honestly, they needed to do that anyhow because the current "dial" implementation is so wonky.
While it is possible that I could overcome (and maybe even enjoy) the right thumbstick as dial model, it was impossible for me to tell because the trial version was ridiculously short. Less than 5 minutes into the game it reset and prompted me to purchase the game.
Next, please.