I'm not a fan of strategy games generally, I usually find them boring and don't have the patience for them. This game makes up for it with the RPG elements.
You start in control of one army, play through the tutorial, and then you're onto your first choice- ally with a tyrant king, or a rightful king. The Tyrant isn't necessarily evil in this world, they just rule with an iron fist.
Your choice is the first step on the morality meter, going from Old Faith (Sidhe) to Christianity, and Rightful to Tyrant. You get different spells, units, abilities and bonuses dependent on your faith. It also affects the outcome of missions- will you ally with one religion or oppose it?
There are several kinds of adventure (missions) that you can access- Battle (you know you're going to fight from the start), Trade (Trade either food, gold, artifacts or women), Diplomacy (Chance of fighting based on either how you answer/your faith/to which outcome you select) and then Adventure (The best kind, you choose a knight to go through a text adventure with, and how you choose determines who joins you, how many units you lose, what bonuses you get etc)
These adventures pop up from time to time, and have time limits on them in terms of seasons. It's easy to keep on top of them at first, but around level 20 when you've got various armies contesting you at the same time, rebellions cropping up in your towns and cities, religious wars and keeping your allies happy to contend with then you're hard pressed to do them all without giving too much ground away. (I do have the Downloaded content so get an extra 9 missions and 2 companions but that shouldn't make too much difference to the number for those without, you'll still be busy).
Units are the typical fare; light infantry, heavy infantry, spearmen, archers and cavalry, and the multiple options therein. You can have 12 knights total, and 3 in reserve in case they die or you choose to dismiss someone. You will require multiple armies.
As for the Knights themselves, there are different classes and all the same attributes to choose from; Leadership (Less upkeep cost for the army,) Reign (More income from each Knights province if they're a liege lord), Adventure (More exp from missions and more movement points on the map), Fight (5% more dmg and hp for the knight and his unit with each level) and Magic (all knights use mana, champions and warlords for melee, sage for powerful spells).
There are masses of artifacts in the game, some of it needs to be used to unlock the extra stats, some provide extra skills, some just attribute bonuses- plenty of choice to match your play style.
You can also choose a wife for each knight, which give different bonuses- either suited to battle or liege lords, and always with at least 1 negative point to balance it out. Just don't marry them off straight away, you can get upgrades to get a new maid sent your court every year.
When you capture your first city you choose which buildings to construct, for various bonuses, and also need to choose upgrades for your troops. Levelling up, upgrading and building can only be done in Winter (no one moves in winter).
There is also an expansion in the works already (this game has been out for a while on Steam).
As for those who prefer strategy, you have unit formations, forests/swamps/hills which can turn the tide for one unit against each other, hiding bonuses to attack, fog spells to confound archers, sunlight spells if your enemy is stronger at night, buffs, healing, freeze spells, slow spells, kill everything in sight spells and victory locations (holding these cause the enemy morale to drop quicker, handy if they're stronger than you).
You also have to prioritise enemies/events on the map
The only reason it gets 4 and not 5 stars is the game launcher has a habit of crashing for some people.