Despite the "been there, done that" aspect to this expansion, it had a winning campaign gameplay formula...
The first Heroes IV game had six maps where there's no inter-relationships, so basically it's six mini campaigns. Thus the only kick comes from the graphics makeover and the hero unit feature, whereas this first expansion did it right by uniting the six maps in a way that it gets a real climatic gameplay experience at endgame. Yes, it's sort of an overdone and cliche thing where each map had a main hero that levels up into an obscenely godly walking tank and collects artifact pieces to beef themselves up even more and meet together at the final map for some serious butt-kicking. Take a read again at my previous sentence. This is the reason why I enjoyed it so much. Heroes IV presented us a new gameplay idea (heroes as participating units) and this expansion further abused the formula, and I think it works.
KingLim