Was great, now greater!
The campaign is long, challenging and diverse. As a long time Heroes of Might and Magic player (HOMM1-5), I appreciate the care that went into emphasizing the differences between the 5 races and ensuring that the creatures appropriately reflect these differences.
The fact that this game crosses several genres (Puzzle/Strategy/RPG), runs the risk of alienating purists. My advise instead, is to embrace this games creativity and diversity. Highly recommended.
Update: After playing the game heavily for a week I wanted update my review to plug the 2 vs. 2 multiplayer option. My son and I have battled the computer 6 or more times using this mode and we love it. The ability to plan out 6 moves cooperatively adds a whole new strategic dimension to the game.