[English isn't my first language so sorry for any mistakes]
When I came across this title, I was intrigued by the art style. This was the main reason why I decided to watch Yami Shibai.
At first the art may be discouraging, especially the way everything is animated. But I got used to it quite quickly and honestly appreciated it. It actually suits the concept of the series. It's as if you were watching a little theatre of horror stories, indeed. Actually, there appear creepy creatures and the way they are drawn can give chills by itself.
About the stories: I can't say every of them caught my full attention. Some are better, some a bit worse. However, a few of them give this disturbing feeling while watching. Are they scary? Well, not necessarily, although as I said they can leave uneasiness to an extent. It's all an individual experience.
As a whole, I found those 13 episodes entertaining. They also give a glimpse of those small japanese folklore stories so surely some people may find it interesting.
Every episode takes less than 5 minutes to watch so I'd say it's a good suggestion as a break. Also, I think the unique art style may be entertaining to some people looking for anime with different looks.