The Last Starfighter

Uridium (released for the NES as The Last Starfighter) is a horizontally scrolling shooter designed by Andrew Braybrook for the Commodore 64 and published by Hewson Consultants in 1986. The game consists of fifteen levels, each named after a metal element, with the last level being the fictional metallic element Uridium. The manual quotes Robert Orchard, who invented the name, as saying "I really thought it existed". Uridium was ported to the Amstrad CPC, Atari ST, BBC Micro, MS-DOS, and ZX Spectrum. A version was released for the Nintendo Entertainment System in 1990 by Mindscape.