1. Yeah, the game arena was not what it was in the first movie. But what I found more egregious was that in the first movie, they really made the world of the grid look bizarre and fantastic with the glowing suits and everything. It didn't seemed like they even bothered with that this time.
2. Sadly, half of the action films that are made today rip off something from the Matrix.
3. Yeah, the mystical stuff bugged me, too. Particularly since, in the first movie, they followed their own internal logic pretty well in advancing the simple plot. All of the people interacted with in the grid were representations of actual computer programs, with the idea being to use the TRON program to shut down the out-of-control Master Control Program. In this sequel, they called the people "programs", but I don't think they really represented anything. What kind of computer program does a flamboyant nightclub owner represent?
4. Yeah, I thought that the young Jeff Bridges could have been done a lot better. I probably could have forgiven it if they didn't also didn't put him in the "real world". Gollum and the blue people in Avatar moved and looked a lot more natural, so I'm not sure what their problem was for this movie.
Yet, despite these shortcomings, I still managed to enjoy it. I thought it was still visually amazing, and I enjoyed the action despite the pointlessness of most of it. And then, of course, there is Olivia Wilde.