I think I understand what loop is: gather materials, build your iron sword, go fight the fungus monsters, turn them into the thing so you can activate the big thing.
But unfortunately I have to echo what the others have said; I can't manage to craft anything or add items to the furnace. A way to check what items your carrying, a hotbar, ability to drag and drop items, or just putting buttons so you click iron bar -> makes an iron bar. All options that could help. I pressed each key on my keyboard, but couldn't manage to add anything into the furnace.
Unless it's the WEBGL/godot getting in the way; exiting fullscreen and entering back in will break my movement input, stopping me from moving.