The game wants you to think and to notice things. No handholding, fun mechanics, plenty of situations in which you'll be like "No way! This game is awesome". Warning, the beginning is a bit cheesey, but once you get to Venice you'll be able to really start appreciating. It's "the longer you play it, the more you come to appreciate it" kind of game. Truly a hidden gem.
The game is split into short campaigns or scenarios and they all seem to have some unique mechanic to them(not sure if all of them do, haven't finished the game yet). If you want to be challenged, hard is probably the best difficulty option for you, on medium you're allowed to mess up a bit too much without really getting punished for it.
When I bought this game, I was expecting HoMaM 3 with a new coat of paint. But Songs of Conquest is so much more. Mechanics like high-ground, attacks of opportunity, penalty to ranged attacks after moving and the changing verticality of different maps make it a familiar but fresh experience. Having limited space in a single city, forcing the player to choose which buildings to build then expands on a similar idea that was present in HoMaM 4. Overall, I feel like tactics have become much more important in this title than they have been in the past.