Zaxxon is an isometric shooter arcade game, developed and released by Sega in 1982, in which the player pilots a ship through heavily defended space fortresses. Japanese electronics company Ikegami Tsushinki is also credited for having worked on the development of the game.

Zaxxon was the first game to employ axonometric projection, which lent its name to the game (AXXON from AXONometric projection). The type of axonometric projection is isometric projection: this effect simulates three dimensions from a third-person viewpoint. It was also the first arcade game to be advertised on television, with a commercial produced by Paramount Pictures for $150,000. The game was a critical and commercial success upon release, becoming one of the top five highest-grossing arcade games of 1982 in the United States. Sega followed it with the arcade sequel Super Zaxxon (1982) and the isometric platformer Congo Bongo (1983).

The objective of the game is to hit as many targets as possible without being shot down or running out of fuel—which can be replenished, paradoxically, by blowing up fuel drums (300 points). There are two fortresses to fly through, with an outer space segment between them. At the end of the second fortress is a boss in the form of the Zaxxon robot.

The player's ship casts a shadow to indicate its height. An altimeter is also displayed; in space there is nothing for the ship to cast a shadow on. The walls at the entrance and exit of each fortress have openings that the ship must be at the right altitude to pass through. Within each fortress are additional walls that the ship's shadow and altimeter aid in flying over successfully.

The game is controlled by a four-directional joystick. On arcade cabinets this is an aircraft-type stick with a molded hand grip. Pushing forward makes the player's aircraft lower in altitude and pulling back makes it rise. The aircraft cannot move forward or backward; it flies at constant speed. As this sort of control and movement was not common in video games, the arcade cabinets have illustrations around the joystick to indicate the effect of each position on the aircraft.