So after a lot of playing this has only happened to me once.
I was playing normally, mining away at resources, my game slowed and lagged and then in the space where it normally shows blocks turned into my camera! It was lagged and slow and did not work well. I have no key on my phone that goes directly to the camera, it was a completely random event. I quit out the game and it restarted fine to my last saved point.
Anyone else had something like this happen? I thought it was nuts!
It didn't go to another app, the camera screen was playing IN Aurora Feint, inside of the area where the blocks are only, the rest of the screen was the same (display # of resources, crystals and boarder). I don't know, the camera was slow and choppy, so that is the lag I am talking about.
Have not played much since this happened, but it was weird.