CD Projekt Red's trickery is to blame for The Witcher 2's replayability. Whereas many games focused on choice plainly state which side of the moral compass your decisions fall on, The Witcher series is much more subtle and devious. The results of impactful decisions don't manifest immediately. Instead they fester in the game's memory, rising to the fore hours after you make them. Time and time again I was surprised at the impact of seemingly trivial judgment calls. Save peasants from a burning building, and somewhere down the line they might return and offer you a gift. Convince an angry mob to spare a suspected criminal, and days after the fact that suspect becomes a powerful person in The Witcher's world.
Beyond interface complaints, the action of The Witcher is not paced well at all. I loved the richness of the setting and learning about the various kings and their eponymous assassins was fascinating, but even a good cutscene can grow long. Momentous conversations lumped on top of one another peppered with a meaningless "action" sequence like walking a prisoner only annoyed me, doubly so because I wasn't allowed to save or drink the potions needed for the fight I was anticipating.