Let's get this out of the way to begin with. If you've played any of the Dynasty Warriors titles put out by Koei (excluding the first one, since it was a straight-up fighter), you won't be getting a 100% revolutionary experience with Samurai Warriors. It's more of the same, with you taking one of fifteen characters across a number of battlefields, mercilessly taking out hundreds of soldiers as you try to take down the opposing enemy commander.
HOWEVER, SW brings some changes along with the tried-and-true beat'um up action. There's a greater emphasis on in-game missions now. Before, you just looked at the map prior to playing the level, made a quick plan of action, and then you went about eliminating all of your enemies, perhaps sometimes reacting to an event that was triggered by something or other. In SW, you're almost always running around trying to accomplish some goal, whether it's helping a fellow officer against the enemy, defending a fort or outpost, chasing down a fleeing enemy, taking over an enemy fort or outpost, etc. In fact, the missions can sometimes totally own you during any given battle, with you spending most of your time running back and forth across the map in a sometimes vain attempt to fulfill the objectives.
Of course, the easy solution to this is to simply sit back and pick and choose your objectives. You can always go back and replay the level in order to, say, defend an officer who was taken out earlier because you had to capture the enemy's base camp. In some levels, you actually CAN'T fulfill all of the objectives, because sometimes you'll have to choose between two or more options, which will cause you to go down a certain path that involves individual missions that branch out from the initial choices, such is the case of Masamune Date, who always ends up facing two different armies in every level. In his levels, picking the option to attack one of the armies will automatically stop you from accessing missions relating to attacking the OTHER army initially.
All that aside, I'll get to basics. You pick a character, play through their levels, and gain in rank and increase your stats depending on how well you did in the levels. In the DW titles, you just picked up powerups from smashing crates or beating enemy officers, and that increased your attack, defense, health, and your musou meter. In SW, your stat growth relies upon stuff like the time left in the stage when you beat it, the number of people you KO'd with your musou attack, and so on. You also get skill points that you use on skills which customize your characters. There are skills that will increase your reach, raise the power of charge attacks, increase the effectiveness of healing items, and so on. There are also special skills that all cost 1000 skill points apiece that can do stuff like allowing you to use your True Musou attack instead of the regular one (the True Musou attack is normally only available when your health is very low and in the red), allowing your ranged attacks to break the enemy's guard, and so on. It's kind of annoying at first, since it was obviously easier to max a character's stats by picking up powerups, since once you hit Rank 20 in SW, your stats can't get any higher, AND you can't get anymore skill points (I think). It doesn't seem as bad the more you play, though.
The Create-An-Officer mode is also improved (sort of) over the one found in DW4. In DW4, you picked whether you wanted to make a male or female officer, you chose their appearance (which was quite limited. You picked a head, an upper body, wrists/hands, lower body, and feet. There were also only about 3-4 different themes, so that didn't equate to THAT much), their weapon, and that was it. In SW, you pick a character model (there are six total for both genders, equaling 12 overall, four of which are locked to begin with), then you go through a training mode where you spend 12 months (12 training activites) making your officer better. This is kind of annoying, though it's not too bad once you spend some time with it. Basically, each activity will raise certain skills, and lower others. Also, as you progress, you'll unlock new training modes. There's stuff like archery training, where you have to take down enemies with only ranged attacks while keeping them from crossing the bridge you're on, there's melee training, which sees you basically taking out as many enemies as you can before time runs out, and... well, there's quite a few. At the end of this 12 month period, you get to choose a clan that your officer will join, and each clan has two trials you must pass in order to join. These trials are basically just the training modes. This can be frustrating to a degree, since the trials will reflect whatever difficulty you reached while training, so if you pick a clan that features the melee trial, and you played that enough to get it to Veteran level, you'll have to survive the trial on Veteran.
Anyways, your performance in these trials will have to gain you 100 points or higher. In other words, your best bet is to do as good as you can to ensure that you get at least 100. the problem with this is that if you fail, you aren't accepted, and you more or less "lose" the Training mode. Therefore, you're forced to start all over again. Other than that, this Create-An-Officer mode is NOT too bad, but it's also a bit annoying at times.
The sound in this game is decent, too. The music, while not as... let's say "prolific" as it has been in the DW series, works. It's a combination of a sort of traditional oriental sound with techno, and some rock. The voice acting is pretty good too, featuring a number of key names from the world of anime/game voice acting, who you've probably heard somewhere else before. Sure, some of the characters sound a bit annoying at times (not to me, really. Kunoichi, the resident female ninja, gets a bit bubbly... well, most of the time, and Okuni, an umbrella-wielding priestess, sounds... well, she sounds WEIRD, but I don't mind), but there's nothing BAD. Not like DW3's Yuan Shao. *shivers* "Very well... I will accept the position of GRAAAND commander!" Well, that doesn't really convey the "GOOD GOD" sense of horror that you can get from hearing the line. You just have to hear it for yourself to understand.
Eh. I'm sure I missed a few points I meant to cover, but I somehow doubt this review will even be read, let alone criticized for lacking certain articles of info, so THERE.
Overall, this is a nice title, if you enjoy running around beating people up. Despite it missing some things that had been made into recurring features in the DW series, it still holds up, and I know it'll grow as the inevitable sequels start to roll out. Plus, despite some of the downsides, I still think this a great title.