Following on from its predecessor, the film presents us with young versions of Kirk, Spock and the rest getting used to each other and to the Enterprise. We start with the tail-end of a separate adventure, in the course of which Kirk manages to break just about every Star Fleet rule, and probably a few they haven't thought of yet. This is, of course, a time-honoured way of starting an action film (including pretty much every Bond film) and offers a way of opening with a bang without skimping on the set-up for the main story. This section is fun, and could quite easily be the end of an episode from the TV show.
We're then introduced to the villain, splendidly played by Benedict Cumberbatch, who blackmails a grieving father into starting a campaign of terror that has an ulterior motive. Without giving away too many spoilers, both he and another character in the film have strong connections with a past Star Trek film, while a scene fairly late on is also an obvious reference to the same film.
The Enterprise is sent on a secret mission to find Cumberbatch's character — known initially as John Harrison — in hiding on Kronos, the Klingon planet. All is not as it seems, though, and Kirk has to negotiate his way between enemies on all sides, inside Star Fleet as well as outside, but to survive and to do the right thing.
For the most part, the principals seem well cast. Chris Pine combines both the raw energy and mild obnoxiousness William Shatner brought to Kirk with the bumptiousness of youth, and Zachary Quinto is uncannily like a young Leonard Nimoy. Karl Urban as McCoy is somewhat sidelined, although he does get the occasional Dammit, Jim, whereas Simon Pegg's Scotty has a lot more action than was usual in the show, and he generally handles it well. Zoe Saldana is good as Uhura, but I can't say I see a lot of the mature Uhura in her, and I was surprised to find her and Spock an item. There is a scene in The Original Series that could be taken as a reference back to that, but I think Uhura was simply teasing Spock then.
Perhaps the biggest reality gap is that a ship as important as Enterprise would be crewed with a bunch of youngsters as its senior officers and someone barely out of the Academy as its captain. In the first film, of course, it was an emergency, but, instead of rewarding the young people with commendations and promotions, Star Fleet has apparently turned over one of its proudest ships to them. It takes enough suspension of disbelief to build a bridge out of — but, then again, there'd be no film if that hadn't happened.
With so large a "regular" cast, there aren't many other significant characters, besides Harrison and a guest female science officer, but the few who are more than bit-parts work well. Harrison's blackmail victim is played by Noel Clarke, Mickey from Doctor Who, making him one of a select group of actors who've appeared in both franchises. I'd like to have seen more of his character.
There are a few retcons, though probably no more than between TOS and the later versions. In particular, the Klingons have had a makeover, but nothing as radical as the update in the 80s (which, of course, they don't like to discuss) — they still look essentially Klingon.
I think my principal doubt about the reboot as a whole is a matter of feel. A lot changed in Star Trek between The Cage in 1965 and These Are the Voyages... in 2005, but it had an unmistakable feel throughout all its many incarnations. I'm not entirely sure the new version shares that — there seems to be less of the strategy and negotiation that was key to so many stories, and more big explosions.
That isn't unique to this film, of course: it seems to be getting more difficult to have anything that balances action and thoughtfulness. They've got state-of-the-at special effects, and they're gonna use them. Now, I like breakneck action and explosions as much as most, but not at the expense of intelligence and thoughtfulness. I'm not saying Star Trek Into Darkness is without these, but I do get the feeling that it's been dumbed down a little to fit in with current trends, and I find that a pity.
On the other hand, perhaps I'm being a bit churlish. If I were coming to this with no preconceptions, I'd probably find it highly enjoyable — and, in fact, I did find it enjoyable. Rebooting a franchise is a delicate balance wherein it's impossible to please everyone, as the makers of Doctor Who have found. I'm certainly happy to stick with this new version of Star Trek and see what they do next.