Total War Battles: Shogun is a spin-off title of Total War series. It's still real-time strategy, but is much smaller-scaled and battlefield is divided into hexes. Ok, I lied, it's more of puzzl-ish PlantsVsZombie-ish strategy. It first came on iDevices before it got ported on PC and it contains microtransactions, but you can beat game without bonuses. It also comes with Sendai Faction DLC for Total War Shogun 2 as bonus.
Now, if you expect normal Total War gameplay in this mobile spin-off then you should just ignore this game. There is no strategic grand map, everything is done on battlefield. Forget about formation and army of troops or any sign of epic battles if that's what you enjoyed, you control individual units here who can walk only forward.
The battlefield is made up of few long lines of hexes. Generals and their bodyguards are at the left and right end of battlefield. Each player can build their base on their own side... Well, more exactly, player can built his base on left side, while AI already has all the needed buildings pre-placed. It will make you remember some block-based puzzles, as each building takes not only single hex, but also sets roads hexes around, which shouldn't overlap other buildings either. Connects some types of buildings as well. One thing for sure, it will take effort to squeeze extra buildings into little space that you are given, but worth it.
Once you set up building, you can train units there and constuct extra buildings as well. Buildings also start to generate recources. And if you put building near corresponding terrain (woodcutter camp near tree), you can get some extra, as clickable icons will sometimes appear, enraging those who hate anything related to smartphone gaming.
Once you build the unit, you can drag it to spawn it at your side of battlefield. Another thing you will notice, is that units can more only forward, as well as move to either below or above line of hexes (this ability has a cooldown to it too!). Units can fight in melee in three forward directions of hex they stand on, while ranged attacks can hit only targets on same line. So yes, once troops goes offense, you can't going to be able to return them to defend your base. AI also loves to spawn units behind your army when you reach his side, making you care of defense once again.
One thing for sure, is that the game draaags ooooon... Units move slow and recources don't rain off the sky either, so it's very slow-paced game.
On good side, at least fighting itself looks pretty, units exhanging blows between each other. Yes, the counter system of paper-rock-scrissor is still there, but they feel more on "have higher chance of winning", I seen few occasions where Samurais, despite being weak to cavarly, were able to kill few cavarly units in a row. (protip: Spam Samurais)
You also can freely start to "build" (focus) General's powers as well, which work like powerups. Always have few of those in making.
Now, as for modes, there are Campaign and Skirmish. Multiplayer was ommited from PC release, which used one screen anyway and would be damn hard to play on PC. There are six Skirmish battles to choose with three difficulty setting, which isn't much to write about. As said it flows slowly and feels like AI has a head-start with recources, but starts to lose slowly as battle drags and drags on.
Campaign, like in many strategy games, serves tutorial purposes, slowly introducing new units and abilities over the course of it, also bringing unique challenges as well. Plot got nothing much, being just text (with voice acting) introduction before each mission, all the excuses why one clan decides to go Shogun. Because you are good guys and they aren't! Unlike main Total War series where you want domination for the heck of it.
Some of the missions unlock few other extra-hard missions, completing which rewards you with extra experience. Tutorial wheels are taken out here and they are real challenge. Or chore.
And yes, being a port of mobile game, it has one of the big evil around: microtransaction. You can purchase extra bonuses and upgrades outside of missions with either limited experience or with money. In all honesty I never tried to purchase anything there with real money, I don't know if it currently works. One thing I can say for sure: Campaign is beatable without any of those microtransactions! And it doesn't feel like difficulty was buffed up on purpose either, at least to me. (They will help to make battles feel less of drag though)
The graphics aren't exactly on top, but art style is nice and fighting animations are pretty enough to look at. Music is forgettable, but will provide your ears to listen to something fitting during gameplay.
So, Total War Battles: Shogun is not so much of bad game, but it's not exactly good either, just... average mobile strategy. Even if enjoyable, I really can't wrap my head around to who I would recommend it on PC, so... not recommended.
That said, also remember that you get Sendai Faction DLC for Shogun 2. You can treat it as DLC bundled with extra game, only somewhat increasing overall price this way.