・Implement player movement, attacks, AI movement and attacks

The next step is to implement Redo and Undo. And next, I would like to implement switching between 2D and 3D display.

Godot version 4 has Node2D and Node3D, can these be mixed? It would be useful for debugging if we could configure it as follows.

Node (Root Object)

-- GameControl (Node + Script)

-- Node 2D

---- Tiles

---- Units

...

-- Node3D

---- Tiles

---- Units

...