The Mount and Blade series is one of my favorites. I'm summing this post about the series rather than an individual games in it because unfortunately, the games aren't really that different.
The game can be called an RPG of some sorts. The concept of the game is quite simple really. You start off as a nobody; a single unknown individual. As you progress through the game you slowly build up an army and gain renown. At first you do this by doing mundane work such as delivering items from town to town or simply delivering messages between the lords and that brings me to the world map.
The map is where you spend a majority of your time even though it doesn't seem that interesting due to its simplicity. All you see in the map is a few towns, villages, armies, and some basic geographical elements. The armies, like one one expect from a world map are represented by a single unit and the geography lacks variety. All factions look the same except for the different font color. That's how the game might seem at first.
Given time, the game gets deeper. Despite its simplicity in some areas in offers a deep and rewarding experience. As you progress through the game (as long as its good progress) you will build up renown, join a faction, make friends and enemies. Best of all, you engage in politics. You have the power to start wars between factions and given enough renown, persuasion or a big enough army you can end them too.
The battle system is surprisingly well-made compared to the setting I described. The game allows you to use small melee weapons (swords, axes and maces), large two handed weapons, bows, spears, guns and grenades. And best of all, you can engage in mounted combat. In fact, you start the game with a horse. Needless to say, different weapons serve you well in different situations. Your movement affects how you swing a weapon and how hard it hits. Momentum can allow you to two twice as much damage and that especially applies to sabres and spears. I particularly enjoy using a speeding horse to slash around infantry with my sabre. What I really hate however is to charge towards another speeding horseman with a spear and I get impaled with that spear. Man I hate physics sometimes.
The game has a very loose story. It's sort of a sandbox game but there are sometimes quests that offer to guide you towards a specific goal. With your help you can help a wronged heir back to the throne, or a former queen to get it back. That is if you don't want to help current lords with their business. You can do them all in fact due to the sandbox nature of the game.
The game can get boring once you help a faction rule the world but once you do, you can just help another claimant take the throne and rule the world. I wouldn't be interested in ruling the world twice, but some dedicated players have done it.
The process from being a nobody to a leader of huge armies is a time-consuming one. Dozens of hours can be spent in this game. Fights might not take that much time, but after a big battle such as taking over a fortress or something you will need to recover, make some money recruit some soldiers to replace the fallen ones, etc. The repetition of these tasks can feel tedious at times, but I personally felt very rewarded when I helped take over a town and was awarded control over it.
Overall this game's shortcomings mostly fall under graphics and unimaginative backgrounds and terrain. The game play more than makes up for those but I'm hoping that they do make another sequel that puts some effort in the areas I mentioned.
Another thing for gamers to look out for is mods for the game. I personally haven't tried any, but a modding community does exist for the game and if its like any game with a half-decent modding community, that can increase the game's longevity by many, many hours.