I really like the gameplay, and I play this game quite often. It's a fun casual game.
There are two deep flaws, however. It has the annoying habit of freezing during the game. Approximately 1 in 7 games can't be finished because the app stops responding to input (on my iPad 3 with iOS 7). Also annoying is that the app doesn't always remember the game you're in if you switch to another app. Depending on how many apps you run and how much time has passed, you can be sure that the app has lost the game you were playing. The app is not updated very often, and this last issue has not been fixed during several updates.
One tip for players: if the games become too easy for you, try wining the game without killing any enemy yourself. Another way of making the game more interesting is to try to win the northern continents without taking any action in the southern continents.