Pleiads is a multi-stage space shoot 'em up in which enemy ships fly at the player in waves in a similar fashion to games like Galaxian and Phoenix.

Ships emerge from a mothership at the top of the screen and swoop downwards in a series of patterns which players must anticipate as they shoot the ships and avoid being obliterated by the Martian onslaught. There are four stages in the game.

Enemy ships come at you in scrolling waves. Growing bird-like ships swoop down at the player's ship as more enemy ships spring forth from the mothership. During the final wave, the player must navigate around parked ships to hit landing pad right on.

The Centuri marquee incorrectly spells the game as Pleiades but the software ROMs and main screen spell the game as Pleiads.