Kinda of hard to explain. It takes the best parts from games like Shenmue, Zelda, and Morrowind, mixes it all up with weapon creation, rune creation, a focused storyline that changes from your actions and makes a fun game. Unlike other RPGS you don't choose or create a character at the start of the game. You start out as a nameless hero who is in a world with ex-cons, corrupt politicans, egoistical Paladins, and vigilante militas. From there you are introduced to three factions, Paladins, Mages, and Mercenaries and you must choose which one to join. After which you choose how to develop your character stat wise and skills and you can specialize as a melee, ranger, or mage or mixed hybrids.
The days change form day to night, and characters follow a daily pattern. Also, you can't just walk into someone's house or be seen doing so, because the NPCs will warn you to get out, and/or attack you. If you wish to go into to other peoples houses then you must sneak in at night while they are sleeping, and also learn how to pick locks.
It's the attention to detail that makes the game very immersive. It's open-ended game play, but keeps it focused with the storyline. Also, thanks to faction chooses in adds replay value to the game.