The demo is quite nice and lengthy IMO for a demo. I believe the developers stated that the demo is about 10%-15% of the complete game and it's an adventure. I don't have the full version but I did enjoy my time in the demo the first time. It almost sounds like they 'downgraded' this demo: less blood and less debris. I could understand the less blood as it stuck around for a while but reducing the debris doesn't make much sense. I suppose it might prevent the frame rates from dropping but I digress. The demo is a great deal of fun and you'll most likely enjoy it.
My advice for the demo is to have each character focus on only one weapon style. For example, if you acquire a person who has some skills in spell casting but none elsewhere then have them devoted to only casting spells. Whatever weapon style you have your starting character go with stick with it. That way they'll be able to use some of the cooler, high-level weapons that can be found in the demo. There didn't seem to be enough experience in the demo to have a diversified character who could use high level, specialized weapons and be skilled, if only partially, in other weapon types.