Some are good, some are not. Recently I've been reading the Cosy Cafe one. You can easily tell which story is too shallow or too much from the first few minutes.
I don't care much about demos for games, especially if they are treated like they are in the porn games area. Just do 0.1 releases without adding "demo" or whatever because the versioning always gets messed up when you have demo, non-demo updates and so on. IF you want to do a demo, you release...
no, no, not "sister", "mom", "landlady" whatever. There are some devs that want you to name the relationship AND to name the characters: "Stacy", "John", whatever.
One game that kind of defied all the odds to become a classic:
Man of the House
Things against it:
- Unity instead of Renpy
- sandbox
- using models that have been seen in other games
But despite all that the grind isn't bad, there's scenes all around to make it enjoyable and it's completed.