Having read the Sandman series somewhere in the early to mid nineties, and heard various (though vague) good things about this movie, I went along not really knowing what to expect.
The main thing I’d heard was that kids don’t find it all that scary, but adults do. This was intriguing, but judging from the reactions of the audience, it was about right. There were plenty of kids watching the session that I took in, but there was no childish crying or screaming (unlike something like Happy Feet, where there was crying when the action became too furious).
I won’t provide a plot or character summary here: if you’re a fan of Gaiman, or you’re intrigued by fairytale stories that can make grown-ups think too, it’s well worth a look.