I write this after logging ~210 hours into Samurai Warriors: Chronicles and, after finally completing all achievements and finishing the mosaic, I can honestly say this is one of, if not thee, strongest 3DS game available. I should preface this with the fact that, unfortunately, I largely ignored this game for several years. SW:C was a 3DS launch title, of which there were few, and I bought it the day it came out, played it for about 4 hours, and finally put it down; I found the story bizarre, the combat confusing, and the constant stream of missions a difficult mechanic to understand. It was not until three years after that, after shelving the game and ignoring it, that I decided, after reading several very positive reviews saying, "Give it a chance! If you understand it it's a great game!" I decided to give SW:C a serious attempt. And I'm glad I did.
Let me mention at the outset that of the "professional" reviews I've read, all of them, without exception (Gamespot, IGN, Giantbomb), the authors clearly never played more than 3 hours of the game -- I crime I myself was guilty of. First, you can change what your character looks like, and what armor he/she wears, you simply need to complete the first chapter of the campaign to do so; You can change your weapon, you simply need to get friendship with another character high enough; many of the missions are intentionally impossible on your first play through, it's not an error in the game design, you're supposed to come back at a higher level to complete missions with high difficulty; there are high level abilities that reduce the passage of time, this is how your supposed complete timed sequences such as "Kill all enemy officers across the battlefield except Akechi Mitsuhide in 60 seconds."
Anyways, the format of the game is pretty straightforward. You and other important characters from Japanese history partake in numerous battles all eventually culminating in the Osaka Summer Campaign, after which Japan, historically, entered 200 years of peace. During a battle your control your character, and 1-3 other important officers present at the battle when it took place, and you complete strings of missions are given at key points in the battle. They range from the very simple "Defeat 100 enemies to break through their surround" to the medium "Intercept Tokugawa's messengers before they can alert Ieyasu of Ina's death in battle" to the challenging "Defeat all enemy officers and reduce enemy morale to zero before Nobunaga Oda reaches Honoji Temple." There are constant streams of missions, some of which, as discussed previously, aren't intended to be beaten except with an exceptionally high level party. This diversity in picking which missions are the easiest, or which have the best rewards, etc. really makes battles feel dynamic, it doesn't feel like linear progression through missions, because it isn't. There is also a great diversity of missions and battle types. My personal favorite is Retreat from Kanegasaki, which is a 30 minute mission where the only goal is to defend your allies as they retreat, and the Gold mission (Gold gilded missions are the most challenging type) is to ensure all allied offices reach the escape point. If you actually try to brawl it out, you'll lose. You're designed to lose. You're supposed to notice this and began retreating.
There's also a great variety of weapons an skill sets (I was fond of Nobunaga Oda's weapon and his skill set, due to it's strength while mounted) to cater to whatever play style you wish. There is also a tremendous amount of late game content. Many of the aforementioned "Gold" missions are incredibly difficult to both trigger (start) and complete, and since you could bring any character you want into a battle, min-maxing your party for certain missions was very enjoyable.
And, considering you can get this game new on Amazon for $20, I'd highly recommend you do.