The Game: Another day, another alien invasion. But this time it won’t be so easy to fight the aliens off: your ship has a limited supply of power, and your guns can overheat if you force them to spend too much time blazing away. You have to be judicious with your firepower, dodge incoming fire, and hold out long enough to dock with your own mothership and refuel between waves. (Gremlin/Sega, 1981)
Memories: While Space Invaders “inspired” a glut of knockoffs since 1978, several games tried to improve upon the slide-and-shoot formula in later years: Namco‘s Galaxian and Nintendo‘s Radar Scope introduced dive-bombing attacks, Moon Cresta by Nichibutsu replaced the standard “three lives” system with a three-stage rocket, and Gremlin/Sega‘s Astro Blaster brought something else to the table to up the stakes: the game was based on the premise that any spaceship would have limited fuel and ammo.
This perfectly reasonable assumption forces the player to be a bit choosier with his firepower. Space Invaders prevented players from laying down a blanket of fire by limiting players to one shot on a screen at a time; Astro Blaster lets you blast away, if that’s your style, but just know that it’ll cost you dearly in very short order. But the resource management angle of the game isn’t as crippling as it might sound: the “docking” scene isn’t even remotely difficult – it’s possible to make a very cockeyed approach to the mothership and still refuel.
Astro Blaster left a legacy for home video gamers as well: it served as the “inspiration” for Activision‘s hit Atari VCS cartridge Megamania!, to the point that designer Steve Cartwright studied Astro Blaster intently, even carefully noting the arcade game’s pixel graphics and the movement patterns of the alien 
attackers. With the help of a major advertising launch, Megamania! was a huge hit… and then the unexpected happened: the original designer of Astro Blaster interviewed for a job at Activision.
By his own admission, just to make Cartwright sweat, Activision co-founder David Crane made sure Cartwright sat in on the interview, but nothing was said about the remarkable similarities between Astro Blaster and Megamania!. Through retro collections and other revivals, Megamania! has continued to make money for Activision – all thanks to a little uncredited help from Astro Blaster.