Getting Started in Android Game Development | Robert Green’s DIY
The main loop of a game is the part that “ticks” sub systems in a specific order and usually as many times per second as possible. Your main loop will need to run on its own thread. The reason for this is that Android has a main UI thread and if you don’t run your own thread, the UI thread will be blocked by your game which will cause the Android OS to not be able to handle any of its normal update tasks. The order of execution is usually as follows: State, Input, AI, Physics, Animation, Sound and Video.