So I hope I don't have Witcher gaf chasing me with pitchforks when I say this, but Witcher 2 reminds me a lot of Two Worlds 2. Not in terms of quality, Witcher 2 is much better, but the way the areas are laid out, the combat, the quests, the feel.
I can tell that whoever developed Two Worlds 2 (Deep Silver?) was highly influenced by the first Witcher game.
There is an thematic and artistic style shift from the first game to the second, if the first was influenced by Oblivion or other traditional WRPGs, the second has a really heavy Witcher influence.
The games also have a similar graphic fidelity with the occasional bug