We have seen the very first appearance of Ciri, and it is possible (and even probable) that what we have seen is not the final design. I sincerely hope that they will make (good) changes to her design in the time between now and the game's final version, but until then, I must be allowed to criticize what we've seen.
The Ciri we see in the trailer is missing two of the most defining features of her appearance - her hair and eyes (ash blonde; emerald green). Add to that the fact that she looks much too mature, when she was described in the books to have a more eternal child-like appearance, partially thanks to her big eyes. I think what irks me more, right now, is the make-up she wears. She would never be this vain and put on a bunch of make-up for basically any reason (unless forced to by Yennefer when attending a banquet of sorts), so seeing her all lip-glossy and painted like this makes me ill at ease. A clear sign of 'sex appeal' that has out-trumped lore-friendly design, making her appear much too angular and pointed in her face, giving off an air of a runway model rather than someone who has spent most of her life on the road, battling monsters and other villains, experiencing horrible trauma after trauma - the criticism that she at first was mistaken for Triss is justified; the similarities are evident. I had expected more from CDPR when handling the most important character in the entire saga, who quite clearly plays the role of the main character throughout the novels. If they also decide to make away with her massive scar that she has on the left side of her face, I will never forgive them. It was already wrong when they did that with Triss's scar, but Triss is not nearly as prolific in the story as Ciri is, nor is her appearance as meticulously described in the books, as Ciri's is, so I was prepared to be more lenient back then. It was still a horrible design-choice, but being a minor character in the story thus far, I was more ready to accept it, despite the questionable reasons behind it.
It's sad to see that most people here feel that the design is near-perfect. It shatters any hope that CDPR will ever realise their error and make a change. I've had enough of awesomely strong female characters being prettied-up in games for no other reason than to add conventional sex-appeal to the end product; all in an attempt to attract a certain demographic or a certain type of player, whom they (erroneously) assume is a vast majority of their target audience and a big reason behind achieving success on the market. Whenever artistic integrity and lore-friendly designs take a back seat to what is considered 'conventionally sexy,' the gaming medium itself suffers, and it is up to players and developers alike to put a stop to this trend. I am of course aware of the fact that CDPR has done questionable things in the past, and it should come as no surprise that they'll keep shirking their integrity for what is considered 'hot,' but I was not at all prepared to see that they might attempt to do something like that with a character like Ciri. I thought they respected her more, and that they would simply decline the temptation to turn her into a sex symbol. The results are unfortunately already in, with several fans of the games - with no knowledge of the books - voicing their wishes that Geralt will get the chance to have sex with her. Is this really what you wanted, CDPR?