the hard achievement is a lot easier if you play through and get good characters on the easy difficulty first, then start a hard game with those characters.
From what i'm reading in the comments, NO ONE thinks this is the best in the Epic War series. Graphics seem almost cartoony, especially compared to EW4. Hero is useless beyond the first few levels, and there's really no strategy beyond pressing "go" at the beginning of a level and grinding if levels get too hard. The new spell system is dumb. The upgrade system is linear and boring and dumb. the artifact system is dumb. Really a step in the wrong direction.