Bogs down after a while and the buttons become unresponsive. It gets progressively worse until eventually it just freezes up entirely. And it's NOT my phone - all of my other apps and games work fine. Even when this game is frozen solid, I can switch to any other game or app and it works with no issues whatsoever. Seems to me like the game has some kind of memory or resource leak. Restarting the phone fixes it for a little while, but it eventually freezes up again.