Moon Alien

Moon Alien is an arcade fixed-screen gallery shooter credited to Namco and Nichibutsu and licensed to Karateco, dated 1979 in MAME. It is catalogued not as an imitation of Galaxian but as a clone set of Galaxian, meaning the same program reissued under a different title rather than a separate game built in its image. The hardware is a Zilog Z80 driving a vertically oriented 224 by 256 display, played by one or two alternating players with a two-way joystick and a single fire button. Nichibutsu followed it with Moon Alien Part 2 in 1980.