It doesn't do anything unique, it just does a bunch of things other games have done but does it all pretty well. The most notable of these is player agency. Aside from the numerous routes you can take on quests, the combat is very reactive to your actions. Aside from the generic "red barrel explodes when fire is thrown at it", things that you think would work actually work.
-Need to make a lever move but it's out of reach? Shoot a spell at it.
-This vent is spewing deadly gas? Put a barrel on top of the vent to clog it.
-You want to start a fight with some people in a room but you know their friends in the adjacent room will aggro too? Stack barrels to block the door so they have to run around the building.
-Person you murdered won't talk to you when you cast speak with the dead? Cast a disguise self spell before doing that and they'll think you're someone else.
A lot of this was seen with DSO2 but it's just done very consistent with the choices it allows the player to make. Even if you do this very specific thing that is obviously very stupid and would doom you, it ends the game not because the game says "RELOAD SAVE RETARD" but it shows you a cutscene showing the consequences of your actions. The game lets you make choices and that's a very novel concept in an era of games designed by jaded and seething Hollywood rejects that want to make their movie but are settling with making a movie game with safety rails the entire way through.