Like others, this recommend is a shy one. You'll see a number of review emphasizing 'the concept of the game,' which is where I am too. It has a ton of charm and honestly is a good game at the right price point, in my opinion. However, the game presents as being simple, while having a spreadsheet of factors underneath, not all being immediately apparent (for example, troops have a happiness modifier, which isn't mentioned in the happiness tool-tip).

My biggest frustration was that the activity log/letter library (whatever it's called in game) would occasionally stay open with no way to force it closed. Usually I could get it by receiving a new letter and opening that, sometimes I'd even get away with marking a letter unread and re-opening it, but I had to restart my game a couple times to get past it.

My only other big disappointment isn't really a fault of the game, but I'll leave it here for new players - when you take the last capital from another ruler, all their remaining land becomes rebels. This means everyone else nearby is going to swarm in and take the land you worked hard to obtain. The tutorial guides you to take a capital before capturing surrounding cities, but I recommend getting the cities first, if you can.