A short summary of your question
I am wondering whether cpp-engine-game should be moved out of this repository altogether.
A detailed explanation of why you are asking this question
cpp-engine-game currently lives alongside cpp-engine (the library), only separated by subfolders in the src/ folder.
However all the assets used for cpp-engine-game live inside the repository as well, this means this repository contains a lot of code and files unnecessary to the cpp-engine library itself.
This makes it more difficult to discern what parts are for the cpp-engine and what parts are for the cpp-engine-game.
It also makes the resulting repository unnecessarily large for just cpp-engine.
It does however streamline production on cpp-engine-game, allowing it to live alongside its most intimate dependency.