The plyGame components where created to work together. The top-down camera was created to work with the top-down player controller, which in turn needs an Actor component to function correctly.
plyGame is not sold as loose scripts that you can use like you want. It is a system with a lot of parts working together.
Btw, you have the source code, look in the Documentation folder for each of the modules. (that would be, under Assets/plyoung/plygame/documentation/ and plyrpg/documentation/