I can be playing the game normally. Going on missions to rack up some momey for upgrades. Then BAM it starts lagging extremely hard. I can play multiple levels without lagging. It's smooth. Then outta nowhere it lags really hard to the point that if I try to exit it out the game entirely it freezes my phone. But after I close the app & log back on it's fine. I have no idea why it does this. It's literally random & it happens in the middle of a mission. It's never at the start.