Ciri and Ellie
Yes, Ellie knew that Ciri had never played video games before. She knew what Ciri's world was like, and that it involved absolutely nothing like video games. But then again, Ciri should also know that Ellie didn't have a chance to play video games in her world, either.
Except that once with Riley, but she wasn't going to think about that.
"I've only played video games once," she admitted. "Post apocalyptic worlds didn't really give much time for video game playing." She reached for Ciri's hand, and squeezed it lightly. "The only time I played a video game it was Mortal Kombat. That's why I suggested that one -- it's the only one I know."
She then grinned at Ciri, "Good. We shall try together."