A movie whose big ol’ Disney heart transcends its often jarring script problems and the fact that Joseph Kosinski occasionally leaves his actors without a director (particularly poor Michael Sheen, abandoned to just flail about like Jim Carrey’s Riddler in Batman Forever), TRON: Legacy is a sumptuous visual feast that — inevitably — upgrades its 1982 predecessor about a million-fold in the FX department. Garrett Hedlund (charming and sometimes awkward, which actually makes him more charming) plays Sam Flynn, the wandering son of tech-geek pioneer Kevin Flynn (Jeff Bridges), who’s been missing for over 20 years; the prodigal son finds Dad has been trapped in the digital alternate universe of “The Grid,” where the elder Flynn’s alter ego, Clu, rules with an iron fist as enslaved gladiators are forced to fight on super-cool CG landscapes, either on foot or on light cycles (you remember those, don’t you?). Bridges is occasionally made younger via CG assist, which is troubling, but otherwise the whiz-bang special effects are breathtaking — as is Olivia Wilde, playing a hottie “Chosen One” who serves as some sort of link between the real world and the awesome computerized one. A likable joyride, even though it makes little sense — though, admittedly, it doesn’t seem to care. Get down with this groovy piece of bio-digital jazz, man.