I understand that Blizzard intends for these Heroic battles to be tough challenges for top players, and the developers have succeeded in making opponents that aren't pushovers. Still, I came away from these matches feeling like I was playing against a cheater rather than a skilled opponent. Instead of creating computer opponents with strong decks and unimpeachable play styles, it's as if the designers simply turned up the difficulty by suspending some of the rules and balance guidelines for the opposing side. I'd have also preferred the introduction of new classes that were well-balanced enough to be used by human playersas it stands, the bosses feel like the "look-but-don't-play" bosses of the original Street Fighter II, only cranked up to unfair levels of power.
The sense of unfairness reaches its apex with the Heroic version of Maexxna, a final boss that sports the ability to return two minions to your hand for free every single turn. This ability is so ridiculously overpowered that it managed to stop every standard deck in my arsenal and a few that I threw together specifically to try to counter it. I was able to eventually win by resorting to a gimmicky, specially designed counter-deck that works specifically in this match (and would fail against practically any other opponent). Instead of the usual turn-by-turn mix of strategy, tactics, and probability, these Naxxramas battles turn the game into an annoying puzzle, where the goal is to figure out how to counter one very specific power.