I'm facing similar issue too. The whole device is like stop responding or momentary freeze, and I have to wait for quite long before the phone respond. There will be sign tough, the game will start to lag, and if I don't quickly quit the game, it'll get slow and worst. Once, I'm not sure if it's related to this game as I've quit the game, the phone seems responding slow somehow, and when I connect to WiFi, the whole phone freeze, no response at all. Waited for some time, then I decided to remove the battery.