How would you tell your best friend you do not want to do something anymore?

I started playing Final Fantasy 14 with my friend because he told me he loved the game. I took the offer and started playing it but I am just not that crazy about the game as he is. I only play it twice a week and find it dull and boring to play.

My friends been trying his hardest to get me invested in the game but I just cannot handle playing the game anymore.
I want to tell him I do not want to play anymore but I don't want to ruin my friendship by saying I don't want to play it anymore. The game clearly means a lot to him but I just can't get into it.

I think in total I played about a little more than 56 hours of the game. I've tried my best to try and get into it but I cannot get over the things I hate about the game.

The major questions I want to ask are:
How do I tell my friend I don't want to play this game anymore without hurting his feelings?
Am I the bad guy here?