well, I think that a demo should be somewhat easy, to convince gamers to the game. That's why that skeleton was easy. IF it was very hard, many ppl would just give up and not buy the game.
So, you liked the demo and bought the game. How bout a little chalenge? Every "boss" is much stronger. <img src="/ubbthreads/images/graemlins/evilgrin1.gif" alt="" />

Another thing. Are you playing on Hard mode? Cause the demo could be only on Easy.