This is not a problem of the battery or the settings my friend. It is common because it has to spend a lot of energy to play such a game. I bet the phone also will become so hot. I don't know the game but I guess it should be advanced graphics. So you could not do many things for that other than uninstall the game. Is not whenever you play the game disable all other applications which are running in the background. It can be a little help in enhancing battery life.