Everything is perfect, from the perspective of a video games' fan. Even based on the non-canon video game series, it still all fits perfectly. The characters are exactly as you'd expect them to be (Specially Jaskier!). If anything, fans of the games that haven't read the books should be delighted at a visual version of the games' prologue. Even though they aren't canon, CDPR did their best to provide an adaptation that followed the books, so no surprises or distaste for anything presented in the show is possible.
I haven't read the books myself, but I have a good feeling it follows them nicely, seeing as Mr. Sapkowski has advised in the creation of the show, and that he loves his work.
As a show itself, it's incredibly well paced. The Ciri part being the only thing that felt *slightly* dragged on, but if you see this first season as a setup, as is tradition in epic series, then it really shouldn't bother you. Aside from this, you get development and action all very conveniently intertwined.
I had a blast watching it, and it's only making me want to give the ol' games series another go.