These demos are written in C#. You must have the Mono version of Godot to run these.
Languages: All have C#, 2.5D has some GDScript
Renderers: Dodge the Creeps is GLES 3, rest are GLES 2
While most of the demos work with any 3.2.x version, these demos require at least Godot 3.2.3 since there are large C#-specific changes in 3.2.3.