It's not working, failed to start with following errors:
ERROR: load_source_code: Condition ' err ' is true. returned: err At: modules/gdscript/gdscript.cpp:791. ERROR: load: Condition ' err != OK ' is true. returned: RES() At: modules/gdscript/gdscript.cpp:1855. ERROR: _load: Failed loading resource: res://Cloud.gd At: core/io/resource_loader.cpp:184. ERROR: poll: res://Game.tscn:4 - Parse Error: [ext_resource] referenced nonexistent resource at: res://Cloud.gd At: scene/resources/scene_format_text.cpp:182. ERROR: load: Condition ' err != OK ' is true. returned: RES() At: core/io/resource_loader.cpp:147. ERROR: _load: Failed loading resource: res://Game.tscn At: core/io/resource_loader.cpp:184. ERROR: start: Failed loading scene: res://Game.tscn At: main/main.cpp:1596. WARNING: cleanup: ObjectDB Instances still exist! At: core/object.cpp:1988. ERROR: clear: Resources Still in use at Exit! At: core/resource.cpp:388.
This is a known bug and fixed in Godot 3 beta 2. Please use beta2 or rc1 :-)