System memory

Hi,

Since I installed a game on my Mac, the memory used for the system has almost doubled. I tried to remove the app but it didn't change anything. I'm starting to believe that a part of the game took some place in the system. Can you help me to remove software and their bundles ?

P.S. the game I installed is World of Tanks and the memory taken by system is 91.18GB also I installed MacKeeper to try it but I doesn't work and I don't know how to remove it completely.