>> There haven't been any good video game-to-motion picture ever.
LOL, it isn't based on video game at all. There is a series of actual fantasy books written by Andrzej Sapkowski that serves as a basis for the show. See https://en.wikipedia.org/wiki/The_Witcher
However, they made a rookie mistake and started filming Sapkowski's source material in the order it was written, i.e. starting with short stories, which is why the show does not make sense: each episode is a separate story, not connected to previous episodes. They should have started with the 5-book saga, and maybe throw some of the short stories as flashbacks.
Show also lacks the proper introduction of characters and the world's mythology. I am a fan of the books, so it all made sense to me, but wider audience might have a trouble making sense of all Wither abilities, Law of Suprise, etc.