The story is rather simplistic and it's far from the most ambitious attempt at conveying a plot, but it does work.
Essentially Shanghai's Tomorrowland has been chosen as the site of a gateway into the world of Tron. You're being uploaded to play the games (that can end rather poorly). You have to beat team Yellow. The problem arises in the fact that Team Yellow are all beasts at the game and you're hopelessly outmatched. Your team, Team Blue, has been vanquished by your opponents time and again (further rubbed in by a helpful video in the queue showing a compilation of your team's greatest fails).
You should be getting a little nervous as you board your Lightcycle. The odds aren't on your side.
After a short and calm ride you enter the room to prepare for syncing into the world of Tron. A countdown ensues and you suddenly are launched at high speeds outside. The idea behind this section is you're syncing into the world of Tron and all along the outdoor canopy arrows are flashing directing you to your ultimate destination. Let's just say you enter the computer realm with style. One of the coolest moments; especially at night.
After the outdoor portion you slow down and enter a small dark room which then opens up to the game room. You are officially in the world of Tron.
Things start heating up rather quickly. To win the game you have to go through several rings before Team Yellow does. At first it's a close call, but slowly and surely you start beating Team Yellow. Before long Yellow Lightcycles (made possible with projections and a nifty trick lifted from the whitewall tires at Radiator Springs Racer, only this time the mirror image are your competitors with yellow rims projected on) start exploding all around you. You narrowly make it through each ring knocking Team Yellow out. I think it's 8 rings, but someone who has been more recently can verify that.
You finally end your game by speeding through the last ring and entering a cool mirror tunnel for a return to Shanghai Tomorrowland.
At that point everyone bursts out laughing or just asking what the heck just happened (at least that's my best interpretation of it). The reaction was always great. My first ride I got to sit right in the front so it was just me facing a track dead ahead before being launched. I was terrified, but oh my gosh what a ride. It really is just mind blowing.
As to length, it could be longer and I would take it in a hearbeat, but it doesn't need to be. I think it stands up fine at this length and should quickly become Magic Kingdom's premier ride (especially if Mine Train has anything to say about it
).
The story is something to knock it on. It isn't nearly as ambitious or as great at storytelling as Battle for the Sunken Treasure, but is still quite the rush with a cool vibe. A good attraction.