How to design your game? Useful concept 'pattern':
In this article I will try to describe my subjective opinions about how to develop and plan your game using AndEngine, which might be useful for new developers to get started. Why do I think its important to have at least brief plan before starting development? Because its easier to predicts everything at beginning. From my personal experience (I have started development of my game without any plan, it was REALLY painfully to be forced to rewrite many parts of the game, just to add some important features) Also starting with good project structure might be useful in future. Developing game, especially alone is time-consuming task, so why not to make it a little bit easier? So here I will include few of my tips and conclusions.
So lets say you have a great idea about new game, what's next? In my opinion its good to think a bit before starting coding, think about proper structure of your project, think what kind of classes you will need, what you will have to create, good project structure is key to success (or at least pleasant development)
Write it somewhere, think about structure.
Try to draw class diagram, will be easier to imagine everything latter.
Explore engine, for sure many things are already implemented, just profit.
Obviously you rather won't many Activities, in most cases only:
But is it good way to create many activities (activity per 'window') ? In my honest opinion not, first of all in increases loading time (time to switch between activities, so obviously you have to load needed assets) And its quite problematic, with many activities you will end up with many problems with access to objects and different game parts. That's why its good idea to have only one activity, its quite elegant way, and much easier to develop. With this way, you just load your resources once (at beginning) or load needed things 'in a fly' during runtime (depends on needs, and extensibility of your game) From my personal experience it has many advantages, less time to switch between game parts, and some memory gain (less activities) you can reuse more objects this way.
Check diagram posted below, its good way to project your game:
The diagram on the picture above, shows four Scenes in one Activity with this way, we load resources only once at beginning (and meanwhile splash screen is being shown) after successful loading of resources, we simply switch to menu scene by: engine.setScene(yourScene);