Update to Godot 3.x

[aaronfranke]

This game still uses an engine.cfg, so it must be a Godot 2.x game. If possible, it should be updated.

[ObaniGemini]

Feel free to do it my man

[akien-mga]

This is the rough structure for a very early prototype that was never completed, there's nothing to port.

Edit: Didn't mean to close the issue, it's still useful as a reference.