Ignoring books which I as a long long time fan of the series (not even a half year since first book was published) CANNOT FORGIVE.

Terrible visual effects. It got slightly better in second season.

Changing story lines on a whim. Even those that doesn't seem to bear importance in first books but WILL be important in later books/seasons. This feels like producers, writers, managements in general (?) didnt bothered to read whole masterpiece of books about Geralt of Rivia, Yennefer and prodigal Cirilla and are writing it on the knee on the go book by book.

Terrible visual effects. Like really really terrible. Golden Dragon was a pinnacle of it

Surprisingly good acting in most of the cases. Especially Cavil surprised me despite the fact that Geralt was described as exact opposite to Cavil appearance of beefed up Superman and Triss actress was really convincing despite the backlash she got from audience (despite the huge success of Witcher games, Triss in books wasnt described as redhaired). Her acting was great.

Few terrible actor choices whose characters description was clearly stated as exact opposite in the books but at same time ignoring original dark skinned characters ? WHY ignore this ? Why cast a dark skinned actress as character who is described literally as pale as snow and like a twin to certain main female protagonist who was cast by white actress ? I DONT UNDERSTAND who was calling shots here but he/she should have been fired on spot for this. Something similar happened to some aspects of character developments in case of most minor characters but I guess this can be forgiven as they didnt appear in following books at all.

These to aspects totally ruined the show in my opinion despite surprisingly good work on side of most of the actors.

Same happened in second season.

To sum it up : Books are masterpiece, show is not even close but may be entertaining for people who didnt had the honor to read the books yet. For those who read them this might be worth watching once but never come back to it.