This is just a floppy disk icon if you plan to copy Tubular Worldsｪ Demo on a floppy disk in order to give it away.
To install the icon, leave this editor application, select the file "TW Disk Icon", choose "Get Info" from the Finder's File menu, click on the icon at the top left of the information window, choose "Copy" from the Edit menu, select the destination floppy disk's icon on the desktop, choose again "Get Info", click on its icon and choose Paste to replace the disk's icon.
And then spread Tubular Worlds all over the Galaxyﾉ
