Use arrow keys and mouse to point currently you can't do anything, because making lasers or things would be difficult. If someone else is there, you should be able to see them playing. If you really want to test it, you can just open two tabs.
Art from @grifpatch's tutorials Uses 3 digit number codes to represent letters, numbers and symbols, which lets it be read. Uses a list reader and maker to compress multiple pieces of data into one variable.