Tried it out, seems cool, though it didn't take long to bump into a bandit who instashot me in the chest with a rifle and it was down hill from there lol.
Always jump in cover/dodge if you see an enemy with a gun. If they don't shoot in their first turn, they tend to not shoot at all (at least for me).
Yeah the combat is really hard. Either run away or make a melee-oriented character. The demo is too short to get some good ranged weapons.
You can make bow&arrows with the ranged perk really early. Slings even earlier than that. Slings are seriously OP in the beginning considering you will never run out of ammo, and since you can just run, shoot, run, shoot, it makes all but massive groups of enemies really easy to kill. Ranged OP.