Beyond Border

To get this you must buy the ultra weapon. It costs 288 gold. It's completely random but can appears as early as entering the shop following the completion of stage 1. If it doesn't appear, you can quit out to the main menu and hit continue to get different weapons. Keep doing that until you get the gun. Sometimes the game takes gold away when quitting to the main menu. If you lose too much gold, just close the game and reboot it and you got me will be restored.