Uridium
Uridium (released on the NES as The Last Starfighter) is a science fiction sidescrolling shooter originally developed by Andrew Braybrook for the Commodore 64 and later ported to other 8-bit machines. It consists of fifteen levels, each named after a metal element, with the last level called Uridium (a fictional metal element, not to be confused with the real metal element Iridium). In the manual, Robert Orchard, who invented the name, is quoted as saying, "I really thought it existed".
Story
The solar system is under attack! Enemy super dreadnoughs have been placed in orbit around each of the fifteen planets in this galactic sector. They are extracting mineral resources from the planetary cores for use in their interstellar power plants. Each super dreadnought seeks a different metal for its metal converter. Your Manta-class space fighter is transported to each planet in turn, and it's your job to destroy each dreadnought. First you'll have to attack the enemy fighter's defense screen, then you'll have to neutralize most of the surface defenses before landing on the super dreadnought's main runway. Once on board, you'll have to pull as many fuel rods as possible from the metal converters before taking off for a final bombardment, while the dreadnought evaporates into the ether.