Just watched Spider-Man 3. (Yes, it's hyphenated. Blame Sony.) The movie felt both overly long and overly crowded. Seeming contradictory, but entirely possible. You would think "length" and "space" are linked, that a story could be either long or crowded, but not both (and, by that logic, not neither.)

A witty rule-of-thumb for story length is "it should be as long as it needs to be, not a word more, not a word less." The other one I've heard is, "it should be like a good meal, to satisfy without stuffing."

Spider-Man 3 fails in this regard in that it seems written by committee. The film had more than one villain, so each one had very little time to become real. The film tried to reach high in theme, to caution against listening to ego. Its execution didn't match, going more for camp and caricature than introspection and characterization.

To use another word, the movie was not 'tight.' Some parts were clearly self-indulgence on one party's part or another. A style-and-dance sequence that didn't fit the plot. A wasted cameo by Bruce Campbell that didn't lead to any true character development or plot advancement, just a waste of five or ten minutes in hopes of a snicker. The editor was just not on top of things this film.

And so it is also with writing. In the course of developing a story, I will come up with tidbits "I gotta put in." Trivia. A great cutdown line. A pretty piece of narrative. A character with an unforgettable quirk. Something great.

They may all be great. They may all be truly worth the excitement. However, they may still not work with the story. It may slow things down to work in that tidbit. It may confuse the reader to put in the trivia. It may distract the plot to introduce the character.

Another writing adage is "kill your darlings." These lovely and memorable snippets are "darlings." If they fit, great. If they don't, they must go. The point of the story is to sing for the reader, to read forward in a rush, to progress in a logical and clear fashion, and to finish with all threads accounted for (not necessarily tied off, just somehow accounted for.) The parts must serve the story, not the other way around.

Otherwise, it will seem either long, or crowded, or both.