Mount and Blade: With Fire and Sword is an interesting.. Sequel/Standalone whatever it is to Mount and Blade and Mount and Blade: Warband.

While it proudly boasts the classic Mount and Blade style game play, allowing you free roam to do whatever you please in the world; be it conquer it, hunt bandits, or even just run caravans. There are however a few things that make it exceptionally notable from the original game and it's sequel.

The first, and most likely the most noticable is the guns. Unlike the original and Warband, which were set in a medieval-esque setting, fit with Crossbows, Bows and Throwing weapons. With Fire and sword is placed in the 17th century Polish-Lithuanian commonwealth, and as such the game features guns. Most people see this in the game, and are offput by it (Much like many were to Age of Empires III) figuring it to be game-ruining or cheap. Taleworlds have done a good job of it, and the method to which they added guns is quite interesting. Mount and blade is renowned for it's complex systems for calculating damage accuracy and speed, and the way they introduced guns fits perfectly into this. The guns, like any weapon in real life or fantasy, have both pros and cons.
Starting off with the pros, guns are incredibly powerful. A good shot to a person can very easily kill them instantly, and someone without a shield (something the game encourages by making them a bit pricey) can't block the shot. That on it's own would be ridiculously powerful, but it is weighed against the incredibly long reload times, limited shots and incredible inaccuracy. The weapons are treated by the game to be a sort of glass cannon: Incredibly powerful, but on it's own? Useless. Anyone with a mind wouldn't ride on their horse with a gun and without a sword. This makes for some incredibly interesting strategy and thought to be combined with the weapon, as is usual with the series.

The second difference is in troop management. The player can only recruit so many troops from villages at the beginning, this means that they cannot stack up troops as they would in the other two games. Instead soldiers in the earlier game are comprised almost if not entirely of mercenaries. If this were how it were in Warband, the game would be absolutely unplayable. In With fire and sword, however, there are some major changes. Firstly, the mercenaries you build your armies out of can be hired as much as you like from a mercenary camp, and more interestingly, at a mercenary camp you can actually choose what gear your troops have (Much like with companions, although a bit less customizable)
This allows you to tailor your army however you like it, albeit at a cost. This feature is incredibly fun and interesting, although I believe it should have been optional to have the village recruitments for the most part turned off in the beginning, to allow more freedom.

A downside to With Fire and Sword though is the lack of mods. This is of course not the fault of the developers, and much more the fanbase. The game didn't hit as much success as Warband did with the community, despite how well the game compares to it, and so the mod base, compared to Warband, is empty. This is not too bad, as the game on it's own is not terrible, but the loss of things such as Diplomacy hurts.

The game also isn't quite as memorable as the other games were. While the other games had their own original nations, With Fire and Sword draws more from actual history, and so contains real nations exclusively. This means that, while they are different culturally and strategically, they aren't as exuberant and different as the ones in the original games. The original two had everything from the desert dwelling Sarranids to the steppe venturing Khergits and snow wandering Vaegirs. While you could see the cultures they were drawn from, it was still interesting to see them all interacting with one another, and they were distinctly different. Not as many people know the difference between Russian troops and Polish ones as people do Viking and Arabian ones. These features aren't inherently bad, though. They can appeal greatly to a history buff with a passion for the 17th century. It is simply that these features aren't as appealing to a wide audience.

Don't let me dissaude you though, With Fire and Sword is a wonderful game, even if you aren't as into history as some other people are. It holds up extremely well to it's counterparts and in some ways surpasses it. And, if you enjoyed either of the first two games, I highly reccomend you give this one a try, as even if you don't like the game in the end, you won't regret any time spent in it.