The original Last of Us game is probably one of the best, most human stories ever told in video game medium and in storytelling in general. This show is a mix of good parts from the video game (those are all the best parts that people keep raving about) and bad parts that were all added by the writers of the show so the show would be 'modernized'.

So there are two possibilities - if they remain faithful of the game you'll get a good show (or rather 1 season of a good show since the sequel to the game was dreadful), if they deviate too much it's going to be bad.

Judging by the first 3 episodes they will use the good parts from the game to keep the people engaged while inserting every few episodes their new and lame ideas that will impose their ultramoralist 'message' on the 'morally incorrect' world.

For reference the first episode was a mix of stuff from the game and new ideas, the second was almost shot for shot taken from the game, the third was all new content that changed the two side-characters and made them ultra-idyllic and likeable, hence ruining the subtle complexity they used to have in the game.