Galaxians is a variant of the almost identically named arcade game Galaxian. It is a fixed-screen shoot 'em up where the player controls a space ship moving it left and right along the bottom of the screen while firing a laser at the aliens above. The Galaxians start in a formation and move horizontally across the screen. At times a single alien leaves the formation and swoops down towards the player who has to dodge it as well as any projectiles launched. The aim is simply to kill all aliens and get to the next level while avoiding getting hit. The game is over when all three lives have been lost.