This is a game about collecting playing cards. You travel to different parts of the countryside to play against npc's and if you win you get a new card that is slightly overpowered. It's mostly an interactive commercial for getting people to download and play Gwent.
The game is missing the proper rating. It should have a rating based on that it contains violence and mature themes, as it can't be removed in game. It's important that when you play the game as a young child you don't get confronted with themes that are can cause severe trauma and nightmares for a long time. This is only about the experience in game, I could go on about how it breaks laws and such too, but that would not be allowed in a review according to the guidelines.
The rules state that we should give score according to the gameplay, this expansion pass has no gameplay at all and is just the reciept that you payed the ransomware to unlock the full game. If you are looking for the game see Witcher 3: The Wild Hunt , that is an awesome game after payment in full.