Katey Rich at Cinemablend says the movie is a sad metaphor for the phenomenon it's describing:
In making his visually spectacular but emotionally bereft film about people trying to escape the digitized world they've created, first-time director Joseph Kosinski has somehow made a movie that's a metaphor for itself, and full of handy advice for audience members who may be anxious to get out this glitzy, oppressive universe after just two hours inside. Cribbing its plot liberally, and incoherently, from sci-fi adventures of the past and treating its actors more like computer programs than human beings with independent thought, Tron: Legacy creates a computerized and dark world that's intended to be terrifying, but falls so in love with its own digital trickery that it becomes the machine it supposedly rails against. It's a good-looking machine, sure, but one that's all clicking parts and no beating heart.
Jonathan Crocker from Total Film calls it a mixed bag, saying it's "a film that awes and bores in frustratingly equal measure. Visually and musically, it’s a triumph. Dramatically, it needs some re-wiring."
Anne Thompson is doubtful of the film's long-term prospects, saying:
Even with late-inning tweaks from Pixar writers, the story is silly. And while Bridges, Garret Hedlund as his son, Olivia Wilde as his surrogate daughter, and Grid key players James Frain and Michael Sheen do their best to keep things lively, this movie is almost as inert as the first one (it looks so primitive now). But like the first Tron, which had a huge impact on Hollywood, this sequel (which is rumored to have cost more than $200 million) also pushes the frontiers of what’s possible. The movie delivers enough of a wow factor to pull in viewers. But I doubt that Disney has a super franchise on its hands.
Eric Kohn calls the film a "Spectacle of Nothingness" and has some good videos and accompanying links for his review. A highly recommended read:
I suppose “Tron: Legacy” contains enough of a cream filling to justify the hype, but there’s nothing surrounding the cream. The accusatory tone is a byproduct of its overall flimsiness. It works decently as entertainment for at least an hour or so because it distances viewers from the nonsensical plot. The sci-fi component mostly exists on an abstract level; forget about real science. The characters are enjoyably familiar archetypes and thoroughly acceptable on that purely superficial level. (Pixar’s writers supposedly doctored the screenplay, although it seems as though they gave up after the first act, which features the best scenes and fewest effects.) The quest isn’t nearly as problematic as the increasingly diminishing sense of humor that ultimately gives way to self-importance. “Perfection,” Flynn says at one point, “is unknowable.” Such pop philosophy worked in “The Matrix” precisely because the Wachowskis always lingered on the edge of parody, but in “Legacy,” Flynn unleashes his knowledge with a straight face. It’s impossible to take the movie seriously when everything flashy on the screen functions as a spectacle of nothingness.
Look for my thought later, either here, at /Film, or on the /Filmcast.