Great answers guys.
I am loving this more and more. Four games down now, and my first 'win' on Hard. I really enjoyed the challenge of hard, and I cruelly missed out on level 5, which would have allowed me to get Glory, which would have given me 1000 leadership and a chance at the Magic School trial.
And it's all because I took pity on the Dragon in the training school.
I missed out on level 5 by that much.
I found that on Hard, the upgrade fights were close to impossible (except for the cursed ring, which is easy). I couldn't upgrade the staff, or the snake ring, nor could I beat the level 6 tournament. These were all winnable fights on medium (well, not the snake ring - I hadn't seen that before).
Really annoyed.
But I thought I would be sick of this demo now, but no. I've still got to play the Paladin and Mage on hard, and make sure I kill that fricken dragon.