Despite being a bit of a fan of Watchmen, I never made it to the cinema to see the film. I finally watched it after the DVD I'd pre-ordered arrived this week. So, what's my take on Zack Snyder's opus? I guess my first comment would be that it's got a kind of fanboy feel - with the exceptions of the omission of at least one scene (the death of Nite Owl I, though I understand it's restored in the new Director's Cut) and the changes to Veidt's gran plot to end the threat of nuclear war, both of which I can understand in the context of a feature film, there's obviously been a definite attempt to stay as close to the book in visuals and script. This extends even to such minutiae as Rorschach's broken trenchcoat epaulette. As an exercise in filming a comic book, I guess it succeeded, but there's the difficulty that a filmed comic book often struggles to convince, and can often come across as rather risible.
Presumably that's why films like the original (Christopher Reeves) Superman series and the Flash Gordon film were in part or whole played for laughs. It's interesting to note the variety of styles applied to the various Batman films over the years, from the really camp 60s versions to the dark and characteristic Tim Burton vision, which gradually slipped in the succeeding films into more jokey style.
The cinematic vision of Batman was regenerated in some style in the two Christopher Nolan films. Of course Batman has the advantage that the character and its origin is well known to most of the public, enabling imaginative retelling on film and on the printed page to succeed. Perhaps that is the problem with Watchmen - for the public at large this would be a new story, with new characters, many with a rich past (well, rich by the standards of a comic book serial) that had to be clearly laid out to the viewer.