I watched the movie twice, once in 2D and once in 3D (imo, the 3D experience is fantastic). And I enjoyed the movie, as a whole. Some critics rip this movie apart for its poor script, but one must bear in mind the target audience is essentially kids so the plot is simple and straight-forward. Some has also criticize the use of low comedy (the groin-thingy, the airport officer ogling over G.One's piercings) but from what I noticed, the audience takes no offense and just laugh it off, even the kids (although the significance of the airport scene might not dawn on them). As for the sci-fi bit as to how the game characters can come alive, yes, it might be flawed but hey, if we can accept the fact that a bite from a radioactive spider can turn one into Spiderman, or that exposure to a gamma bomb could turn one into The Hulk, why the need to nitpick?
The thing is, the makers of Ra.One didn't set out to make this into an intelligent, gritty flick. It is meant to be an entertainer, and most importantly, to showcase the technology that was once regarded to be a Hollywood exclusive feature. With Ra.One, the aim is to create a superhero that would appeal to Indian children and to show the world stunning visual effects could be achieved at a fraction of the Hollywood price tag. I'd say the team is successful on those two fronts.
The plot is simple. A dad, eager to win his son's affection, creates a game where the villain (Ra.One) is stronger than the hero (G.One). Son is happy and gets to play the game, but when he stops the game at Level 2, Ra.One is angry because no one is supposed to defeat him. So he vows to track the boy down and comes to life. The boy and his mum are forced to flee, but not before G.One is also brought to life to defend them.
Shah Rukh Khan (SRK) plays dual roles, that of the dad, Shekhar Subramaniam, and the superhero, G.One. As the dad, SRK plays Shekhar the way the script demands perfectly - clumsy, endearing, an embarrassment to the son, but when the situation calls for it, is perfectly responsible and heroic. Some say SRK is over-acting as Shekhar but personally, I feel to bring Shekhar to life and to make him a stark contrast to the stoic G.One, SRK had to be ridiculously funny and silly, and in that aspect, he succeeds brilliantly, imo. As the superhero G.One, SRK manages to be mostly stoic with monotous speech pattern, and his posture is impeccable (straight back, restrained gait/movements) though I have to admit it is a little jarring to see G.One smile and groove in one of the song items, Chammak Challo.
Kareena Kapoor as Shekhar's wife is beautiful, and though there isn't much scope for her to display her histrionic, she is absolutely brilliant in the scenes following her husband's death and when she is Ra.One is disguise.
And the little boy who plays the son, Prateek a.k.a Lucifer (his game handle) is truly a wonderful child actor who displays ease and confidence in all of his scenes.
The action scenes are brilliantly shot and look almost flawless, and the visual effects are really quite top-notch quality (nothing as epic as Transformers, of course). I seriously love the train sequence where SRK as G.One flies/runs from/across carriage door to carriage door. Look at the way SRK brilliantly holds his posture in which the action looks real that you forget he is aided by wires.
If I need to complaint about one thing, it is the number of scantily-clad dancers in the song items Criminal and Chammak Challo. Why the need to show so much skin?
All in all, this movie is massively entertaining. You have drama, action, comedy, bit of romance all rolled into one. It is also a game changer for Hindi cinema due to the visual effects and technology employed - proof that Hindi films can retain its desi core and still stand on an international platform.