Hi! That is indeed the case. I remember someone once did a version that added some multiplayer elements to it.
You can make Pull Requests to the original repo if you want to add something to the base game or you can just make your own version.
It's made in Godot 2, mind you; so use the correct version of the engine. After I get back from vacations, I'll try to make the updates necessary to make it compatible with Godot 3.