I won't go through it scene by scene, God knows I don't want to relive it in my mind. I will give it one highlight. The second set piece is quite wonderful. It shows how the superhero class of the mid-40's devolves into dysfunctional set of today, if by today you mean 1985, which I do.
Some points of interest
Dr. Manhattan, the all-seeing blue superhero who is something of the centerpiece of the film, is almost always naked. For a being of such power, he is always limp. Go figure.
All the characters seem disconnected. One is really supposed to have problems relating to humanity, but they all are travelling in their own orbit. It makes for a very disjointed experience.
The plot is not. There's a bit about the aging of superheroes and their place in contemporary society, if by contemporary you mean 1985, which I do. Another bit is that somehow Richard Nixon has served four terms. Nuclear war between the USA and USSR is on the horizon. There's a trip to Mars. A mess, just a mess.
Only one character's origin is explained. That all the others seemed to come by their powers naturally is, I don't know, a given. Rorschach presents a pivotal moment in his life, but he was batshit crazy before then. That's made pretty clear.
Watchmen suffers from taking itself oh so seriously. As a result, it is leaden. I did laugh at some of the gore, that was humorous, but as far as genuine humor goes, there is none. It's almost a given that the best graphic novels turned movies have a solid dose of humor (Sin City, for example).
At one point, Silk Spectre (she of the great butt) says, "nothing ever ends." All I could think was, "yeah, like this movie."
Walking past the posters of upcoming movies, I mentioned to my kids that even Hannah Montana will be better than Watchmen. They thought I was kidding.
Speaking of watches, where can I go to get my three hours of time back?