The movie is a total reboot. And yes, it features time travel. While normally this is a giant red flag, in this case I don't think it's too bad. Especially when you want to make giant, universe-altering changes without pissing off the continuity nerds.
Star Trek starts off with a big action sequence that holds no surprises. You'll immediately notice a few dramatic stylistic changes in the camera work. This movie owes more to the pseudo-documentary style of Firefly or BSG than the traditional pristine look of the last few decades of Trek. Space is pretty silent (although it somehow gets noisier as the movie continues), and they even do the cool thing of making sure that everything in space doesn't share the same Z-axis. Minor, but I love it. The intro ends with an emotional note that resonates strongly; it could have been cheesy but it works.
So, they reboot the universe. We get some Kirk/Spock back story, and some brief moments at the academy. Wacky events occur, leaving most of our familiar characters aboard the Enterprise. We witness each of them rise to their known rank and positions. It's all very wink-wink. Occasionally a bit overly cutesy, but ultimately fun. I found the scoring a little weak (Abrams uses the same composer for everything), but many of the sound effects echo the original sources. The effects are just great: I would expect nothing less than perfect, and I got it.
I particularly liked the Vulcan architecture. Yes, the new bridge looks like an Apple Store, but the glass and white looks modern. It might not age that well, but it's cool. The costumes look forward and backward at the same time. We have mini-skirts on the bridge and familiar color coding. It all works. The Enterprise itself feels HUGE inside. Engineering isn't just a room with a console; it's massive. It has weight. I love it.
I'm not going to go into the story. It's convoluted, but frankly it's really not the key to this movie: this is a roller coaster movie with new actors playing parts we love.
So, let's talk about the most important thing: the characters. They basically nailed everyone. Uhura and Bones are used a lot in the early bits. Chekov and Sulu each have a few nice moments. Scotty shows up late in the game and steals almost every scene he is in. But as the movie goes on, it becomes almost entirely Kirk and Spock, which really is how it should be.
More so than anyone else, Kirk is an impression. But ya know what? I buy it. The Kirk we knew is older. This one is younger with bigger balls and swagger. This kid will chase the skirt instead of just knowing she will come to him. I could certainly see someone thinking they took Kirk too far, but I buy it. He has charisma and some great lines.
Quinto's Spock is great. I resisted the urge to make Sylar jokes (mostly). He's reserved, subtle, and when the need arises, emotional. It works. He's the best casting in the film. Since Nimoy gets to reprise old Spock, we're given the ability to stack the two Spocks up right against each other. And it's just great. I totally buy it.
Eric Bana is the big bad. He seems almost totally superfluous. He does just fine, but I just don't care either way. This movie is about our heroes. Bana's Nero could have been a robot or an entity or whatever. He's a plot device used to press the universe reboot button, and to give us a ticking clock.
Two of the "humorous" sequences go a bit far. You'll know them when you see them. It's like they were inserted to keep 12-year-olds giggling. I expect this in a Disney film, but I wish I didn't see them here. Another action sequence in the middle serves no purpose except letting us have a giant monster chase Kirk. Abrams probably wanted to toss some work to his Cloverfield monster-making buddy.
But here's the thing: Star Trek is entertaining. It has problems, of course. It won't make everyone happy. But by the time Scotty gets into the story, there are so many moments of unbridled joy that you can't help but feel giddy. I don't know if Abrams will stick around or if this cast will be back for more, but if they are, I know I'll be in the theater again. And you should be there too. Now. You're a carbon-based life form who reads Slashdot (and MessageBase!). You owe it to yourself.