One of the games I’ve played on Facebook is called Realm of Empires. It’s a quite involved game of village development and medieval combat. You start out with just one village and a few troops; from there you can conquer huge sections of the world, make alliances and treaties with your neighbors, and try and crown yourself king. (Gee, why would I find this game interesting?)
Positives: it’s a lot of fun to build up your villages and get them nice and strong, so that you can bully the local neutrals into signing on with your empire. The graphics are quite pretty without being disruptive or distracting. The game has a quest system that introduces you to all the game features and gives you bonus gold for learning how the game works – which means you rarely encounter a player who’s just completely clueless about how the game is supposed to work. Setting up your attacks is challenging.
Negatives: the game lacks some verisimilitude; you can support a village with troops from another village, but the supporting troops can’t be “localized” – the city that built a troop is that troop’s city, forevermore. This makes organizing your empire at higher levels somewhat challenging. The map doesn’t show troops in motion, which would be cool and would really bring the game more to life.
Most of the things I find I don’t like are things where the game could be better and cooler, though, not things where the game is bad. For example, it would be great if you could have profitable, quiet trade with your peaceful neighbors. As things stand, there isn’t much incentive to be friends with people other than to avoid having to fight them; being friendly just means you leave each other alone as the game exists. I’d also like to see more high fantasy elements, like court wizards (good on defense, boost village productivity) or higher levels of palace. But these are quibbles.
The game itself is quite fun, it’s easy to play in just a few minutes a day, and it’s free to start. You can buy servants to get access to some management tools but this isn’t necessary until you’re quite into the game, and there are lots of free offers you can do to get more servants if you don’t want to shell out the $5 or so you might need in a month to play the game at the fullest level. Recommended to anyone wanting an enjoyable building/fighting game with a medieval theme.
Here’s a screenshot of the area around my main complex of villages:

and here’s a shot of my army list, of a village about to become part of the Kingdom of Bob.

