I recently watched all 13 episodes of an anime that I really enjoyed. It was ridiculous and entertaining and almost made me cry laughing once or twice. But it had a major problem at the end: there was absolutely no closure.
I know, logically, that this often comes from an intention to make a second season, or the source material (a light novel, or a manga, for instance) isn't finished or has an ending that didn't 'work' for anime audiences (or, you know, things got changed for American audiences). But it got me thinking about the importance of closure and payoff in storytelling.
How many times have you watched a movie or read a book and the ending was a complete letdown? The "it's all a dream" syndrome, or major story lines didn't get wrapped up despite the fact that it was a standalone piece. It's a horrible feeling, isn't it? You're left wondering what happened to the main conflict, or why the protagonist suddenly feels content living a normal life when the Big Bad is still out there, waiting. It's anti-climatic and makes a reader/watcher feel like they just wasted a bunch of time getting invested in the lives of these characters for nothing.
The good news is there's a fix for this. Critique groups and beta readers can help you figure out where your story might be falling flat and, if they're good at brainstorming, help you work on ramping up the tension and cutting out the anti-climatic bits. They're also pretty good at helping to point out plot lines that haven't been wrapped up, or plot holes readers will want filled in. Even the most detail-oriented planners are likely to have a few dangling threads that will drive readers crazy!
So, long story short: don't shortchange your audience. We'll get angry and write vague blog posts about it.
Emily might have had this problem in her latest short story, but it's fixed now. She also seems to get irrationally angry over let-down last episodes of things that don't have another season coming.