Gameplay in Ultimate Domain is definitely its strongest point. It is multi-faceted, varied, and gets deeper and more engaging the more you play, although it bogs down in later stages due to micromanagement (there is no "auto-build" option, for example). As with other empire-building classics, success in Ultimate Domain requires a fine balancing act between economics, military, and research on new technologies. Trade is crucial for obtaining raw material you don't have in your lands, which are needed to construct buildings. Similar to Sid Meier's Colonization, each citizen of the land must be assigned jobs, e.g. settlers, architects, woodsmen, farmers, and so on. Proper allocation of your workforce is therefore key to winning the game.
Ultimate Domain features many nice little touches that set it apart from other games, such as seasonal effects. For example, Fall is the best time to cut wood, and you will need a lot of surplus food to survive Winter. The graphics change to reflect what season you are in, and are quite pleasant to look at (although the overall color tone of the game is a bit dull). Another neat touch is the numerous technologies (here called "crafts") you can research and implement via inventions built by your inventors (who must work in workshops built by architects). There are over 70 inventions you can develop, most of which (such as the balloons and swords) are a lot of fun to observe once they are put in action. You can also hang out in the tavern to listen to adventurers' tips on locations of the jewels, and make offering to the gods in temples to raise the morale of your population.
On the downside, the AI is nothing to write home about. Although the computer players manage their lands quite effectively in terms of resource management and trade, their military tactics are severely lacking. This means that the outcome of most battles are determined more by the number of troops and the level of technology (e.g. whether they are equipped with sword), than by strategic planning. Ultimate Domain also suffers from the same weaknesses that many European games share: below average graphics, and cumbersome user interface. It would be much better if the most important game functions can be accessed from icons on the main isometric map screen (a la Populous), rather than having to click on each building to bring up a separate screen, then click on a few more items inside to bring up a menu where you can do something.
Despite all these weakneses, however, Ultimate Domain is a deep and engaging strategy game that fans of the genre should enjoy, once they get used to the interface and poor graphics. Two thumbs up!