There were many drawbacks, especially the silly daily growth and the two-branch castle upgrade system. And a few well-developed heroes completely replaced creature units, which affected the gameplay (as did the daily growth, when players didn't leave the castle, waiting for "a few more units":D).
I don't know, but after switching to the fourth game, I realized that the tactics had changed completely, and I had to play differently, and I can't blame them for that either. After reaching "expert game" level in the fourth game, I started losing even on easy levels in the third game, simply because the game tactics are completely different!!!!
