How do others keep track of everything going on in their games? I am working on a new game and I am quickly realizing everything that I need to keep track of.

Example:

Maybe a layerManager that keeps track of all the layers and what is happening for a particular scene.

Maybe a sceneManager for sharing objects among scenes

But then getting to game play itself, what if you have 100 objects on the screen each with its own state and happenings, there needs tobe a way to keep track of all of that.

Drawing everything out is really helping me.

Can anyone share with me how they go about object tracking/management? I am seeing a few different managers and then maybe even a parent object that manages the managers..is my thinking way off?

Any design patterns that may be useful for me to read about?

Update: doing some reading and maybe a Factory pattern might apply.