I know that I am an amazing, awesome uber-player, but if - starting from some point very early in the game - I start getting 100% in every level on the first try, something's not right with the difficulty scaling.
I encountered a strange bug in the level introducing trolls: the rest of the wave was cleared but a knight got stuck fighting a ghost near the edge of the screen. (Don't know if the location matters...) I couldn't move the knight ('Can't move.'). While the clerics kept healing the knight, no one else felt interested in joining the fight. I guess the mages just enjoyed letting the tough guy feel his helplessness ;)
This would get 5 stars from me, if it didn't force me to play _tons_ of really easy levels before getting to challenging ones. (And I am assuming they do get challenging at some point. I haven't reached it yet.)
One last thing: The 100 wins claimed to be required in the medium achievement description are a lie. I've got almost 50 campaign wins (those you can check for) and I have done more arena than campaign (I haven't found a way to check the number for those).
You know what's even more fun than vague descriptions. Wrong descriptions: "When his turn begins, Conjurer doubles Golem's power." No it doesn't. Each turn it adds the starting power. 25+25+25+25+... != 25*2*2*2*... It's a world of a difference!
I have a hammer, there's a fresh wall, I better break it open and see what's behind it. But wait, I don't want to make a mess. Seriously? In this house, with everything you've seen so far, _this_ is what you're worrying about?!
If it's a permadeath game, please be kind enough to tell me in the tutorial. The screen that popped up when leaving a floor kinda implied (to me) that I would be restarting at the beginning of the floor. I found out I was wrong after being interrupted by RL, not hitting pause and dying. Really frustrating.