good game, but freezes all the time – 2012 Zombies vs Aliens Review

Great game and love it, but it freezes all the time. I can't upgrade anyone or unlock them; because every time I click on them it freezes and doesn't work. I have to restart the app then open it, and I still can't do anything. Please fix this soon
Review by Holydiver812 on 2012 Zombies vs Aliens.