Hard seems to be "only sometimes" random. I didn't try medium, as i changed to hard after 4 or 5 levels of easy. The extremely stupid AI ruins the game completely, as it has no kind of multiplayer option or anything else that would cover up the really weak opponent.
What's the point of putting clerics back? They are excellent tanks with shields and heavy armor, 2 clerics front, mage and ranger behind them works great. I made it to wave 50 in survival and i got bored, monsters were getting stronger too slowly.
 "Give Up"){kind=icon}
 "Book of Mages: The Dark Times"){kind=icon}
 "Check Flag"){kind=icon}
 "Monsters' Den: Book of Dread"){kind=icon}