Probably the most shocking one is that the plot of the game actually involves something called the "Tron Legacy Code", though nothing like it appears in the film sequel. There are some pretty shocking similarities, though, such as Kevin Flynn vanishing under mysterious circumstances (per the Ghost in the Machine spin-off comic) and Tron himself going MIA. There is also a character who is dead in 2.0's canon and still alive in Legacy's.
There was also a sequel for the Game Boy Advance called Tron 2.0 Killer App (a title which was also used for the Xbox port of the PC game) where Tron was revived from archival storage and teamed up with Mercury to thwart a viral attack on Encom. Jet is shown to be traumatized from his experience in cyberspace, having nightmares and having trouble discerning those nightmares from reality. The game was released to minimal advertising and press coverage, but still managed enough success for Slave Labor Graphics to release a six-part graphic novel series called Tron: Ghost in the Machine that took place six months after the game's events. Ma3a out of desperation and uploaded to the digital world of Encom's computer network to protect it, his father, and the secrets of the digitizer technology from both a mysteriously powerful virus corrupting everything in its path and a group of Corrupt Corporate Executives from the company Future Control Industries ("fCon") staging a hostile takeover. Jet is conscripted by the Benevolent A.I.
It is a Sequel in Another Medium to the 1982 movie TRON the player takes the role of Jethro "Jet" Bradley, son of the film's characters Alan and Lora. TRON 2.0 is a video game developed by Monolith Productions and released in 2003.