I have few ideas in my head:
1-make sure that you've defined all game folders which you have in your project's root folder;
2-make sure that your scripts are placed in defined folders (or in project's root folder);
3-make sure to include all of your own scripts by "" (instead of <> - use those only to include engine lib) f.e. #include "player.c".

I'm sure if you go through all this steps, you'll get everything working laugh good luck!

Greets

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