I have to give major props to CDPR, the story is probably one of the most compelling I've ever experienced in a video game. I am a fervent "games are not movies" purist, I often deride the "story" in games like Mass Effect because I don't think cramming a movie into your video game is not how you are supposed to tell stories in the medium. On the surface this is what the Witcher 3 is, but it is done so masterfully I can't help but be sucked in.
I am not exactly sure what it is, but I think a major part of the reason it works is the ambiguity of the world, the characters, and the decisions you make. You don't really know what is going to happen; everyone has an agenda, everyone is trying to use Geralt, and everyone lies constantly. You get some truths, some half-truths, and some outright lies, without always being able to tell which is which. You get thrust into conflicts between evils and you really aren't sure who is the lesser one you should side with. And often you are put in situations where no outcome is better than the other, they both just really suck. This texture paints the world in such a way that your disbelief is utterly suspended allowing for a high level of emotional engagement.
The Witcher shows the benefit of not having an "alignment points" system that many RPGs contain (which I generally dislike as well). It allows you to make choices based on the context of the situation and the personality of your "Geralt" without affecting parts of the game that aren't your story (no spamming "paragon" because that is your build).
I just wanted to echo this sentiment as others have as well.
Currently I'm questing in Novigrad, dabbling a bit in the Skelli isles.
There has been a lot of bitching about the graphics, but it seems like just a lot of nerds getting their panties all bunched up. Sure, the graphics aren't the best, but it's definitely serviceable, and to be honest, I spend so much time staring at my minimap while running around I don't really focus on the scenery.
Where this game gets it right, in spades, is the story and acting. And personally that's what I play a RPG for. I had finished off playing Witcher 1 and 2 prior to starting Witcher 3, so I have become fully vested in the story line and where the characters are headed.
It definitely is the moral ambiguity that makes the choices so compelling. In most games you can tell which is the "good" and "bad" choice, here you are totally fucked because there is no correct answer. People bring up the Baron questline, which is great. Recently, and I'm not gonna spoiler this because it doesn't give anything significant away.....I helped Lambert, an old witcher friend, hunt down someone who had killed one of his other witcher friends. When you finally do meet up with the killer, it turns out things are not so black or white. I had a genuinely hard time deciding what to do at the end....and I'm still not sure I made the right choice. But I am sure I did make the right choice for me, which is what I would expect out of an RPG. I truly am role-playing. That's awesome, and something I've rarely seen in a video game.
And that's not just an infrequent occurrence. This type of dilemma happens ALL THE TIME in this game.
Which brings me to Triss and Yenen. Having played the first two games, and since Yenen was not in either of those games, I have been siding with Triss the whole time. I romanced her in both previous games, and I chose to go save her in Witcher 2 instead of going to save the dragon-lady (I had chosen the Scoi'tal path). I know from game canon that Yenen is suppose to be the love of Geralt's life, only he got amnesia and doesn't remember this. And I absolutely loved the fact that when I first met up with Triss in this game she gave me the cold shoulder, because that realistically should be her response....the whole "hey I missed you" from me followed by the cold shoulder and "oh, how's Yenen" line from her. Classic.
So in a game full of important choices to be made, choices with no right or wrong answers, full of in-game repercussions....this to me will be the biggest one. I haven't gone far enough in the main quest lines where this has become an issue yet, but I can see it looming on the horizon. I'm going to choose Triss, because having played the previous two games, I am going to stick with the girl I brought to the dance in the first place. But to even care? Kudos to CD Projekt Red for making a game where I actually care about the choices I make.