The endings I got were a bit abrupt, but the fact that I was eager for more is pretty telling that the story (at least) is pretty well done. I do realize this is a demo, but something a little more like 'more to come in the full release' or something other than 'thanks for playing!' and then back to menu.
Other than the story being interesting, this plays like a pretty standard VN. Not that it's a bad thing, but it doesn't really stand out too much. I am eager to see where the story goes, and I hope there are more choices and endings in the main game.