I played it on location yesterday and it always leaves me scratching my head why people go nuts for it.
Tron Legacy isn't John Borg's best work. Almost every game he had made since is better (Metallica, Iron Man, TWD, GOTG, TMNT, etc)
The game play isn't great (it's not terrible), the movie it is based on wasn't good (51% on Rotten Tomatoes), and will likely never get vaulted because costs associated with the license and porting it over an 11 year old SAM game to the Spike 2 platform.
If it was based on the original movie, and not as created as part of the media promotion campaign for the sequel, it might be a different story.