For the unenlightened, "isometric" can be defined as a form of graphical projection - more specifically, an axonometric projection. It's a method of visually representing three-dimensional objects in two dimensions, in which the three axes of space appear equally foreshortened. Clear?
But why do we care? Because in 1982, Sega produced one of those quantum leaps in gaming that are so rarely seen. By displaying games using an isometric viewpoint it was possible to build faux-3D worlds that gave the player an almost God-like view of what was happening. Like the first moving picture or the first live TV broadcast, isometric games took the arcade world into a new era, and Zaxxon was its genesis.
The back-story is an age old tale; Man creates robot, robot kills man, robot builds fortress, robot takes over the world, plucky young underdog in underpowered spaceship tries to kill robot. But the awe that gamers felt the first time they saw the Zaxxon cabinet, with its colourful Lego style graphics and huge flight stick controller aroused the kind of revolutionary excitement that arcades were made for.
The game is a tough one, requiring gamers to control not only the direction, but also the altitude of a brightly coloured paper aeroplane. With enemy ships, gun turrets, diminishing fuel supply and various barriers blocking your way, slowing down is a necessity to take careful stock of your surroundings. But any dawdling will only result in Zaxxon the android sending a homing missile to gee you up, and it's this urgency that costs most lost lives as you send your planes careering into walls through over exuberance.
Zaxxon was also one of a range of videogames that Sega and MB decided would make good board game variants. They were wrong. You cannot replace an innovative and challenging space shooter like Zaxxon with plastic and cardboard any more than you can replace the internet with a cabbage and a squid.