Galaxies, like its parent game Geometry Wars: Retro Evolved on Xbox Live Arcade, allows the player to to control a ship that can shoot and sail in 8 directions. It is primarily controlled using analog sticks and a single button to ignite explosives. The playing area is a flat 2D surface, but unlike Evolved, it is divided into numerous planes (or levels) that vary in size and shape. When assaulting the player, the aircraft is usually a near-black background lighted up with a grid, but foes are brilliantly colored objects that fill the screen with particles and colors.
Galaxies differ from Retro Evolved in that the single-player component features multiple stages rather than just one, each with its own set of scoring goals. Galaxies also introduce a new mechanic in the shape of the drone, which functions as an assistance ship capable of doing one user-specified task at a time, such as rotating shield, secondary shooter, backward shooter, and so on.
The Wii edition includes Geometry Wars: Retro Evolved and may connect to the Nintendo DS to download the demo and access new features, such as a hidden version of Geometry Wars: Waves.
