I've played your game and even managed to beat it, I think!
Raylib is such a cool set of libraries and as others have said, I can't have anything but respect for your efforts.
It's also very kind of you to include the source code.
There's also a small bug in the game: sometimes when you launch the game and press space, player gets teleported somewhere far away. I think this might have to do with uninitialized public 'vel' variable in your Player class, but I might be wrong.