This is coming from someone who played all three of the games and read the whole book series. I imagine the way the episodes jump between time periods could be confusing for those who don't already know the overall story.

Some of the performances in this series are pretty great: Cavill (Geralt) and Batey (Jaskier) both did an amazing job. Freya Allan (Ciri) was good as well. Significant parts of the cast, however, didn't really fit the characters they were portraying from the source material, both in terms of appearance, age, and mannerisms. This gives you a jarring feeling that breaks the immersion to the point where it's borderline cringeworthy.

There were also some major plot details, from the original story, that were changed for no apparent reason, leaving the series with a worse story progression. For comparison, this is the same thing GoT suffered from during later seasons (where the writers simply didn't have any more material to go by). Then again, CD Projekt Red were able to create a fantastic continuation of the original Witcher saga, so it all may just be bad writing.

Also, it seems like producers of fantasy media are very reluctant to adopt the kind of extravagant, colourful attires that franchises such as The Witcher and ASOIAF use for their characters. Instead, they usually seem to opt for a more mellow or "cool" style. Unnecessary, in my opinion. Perhaps one is better off sticking to video games for those kinds of expectations.

To summarize: the show is a mixed bag of great scenes and bad scenes. At times you're amazed at the acting, dialogue, and fighting, while other times you're rolling your eyes wishing for the scene to end.