samgj

So I have to define one myself?

Other people. Not just multiplayer but also AI you could talk to, or trade with, or team up with.

You can only incorporate code from a GPL project if you project itself is GPL.  Therefore you need to add the GPL notice as the header to ALL of your source files, in addition to providing a copy of the license with your source and your executable.

I understand that but, do I have to put the name of the project it's from and if so where do I put it.

I added semi-colons to the classes and removed new from create_instance. There are still errors but they are for unrelated problems and I understand how to fix them.

It's in the function create instance here