Imagine Earth - Galaxies is a simulation DLC for Windows that expands upon the core gameplay by introducing entire galaxies with up to 20 planets for players to colonize. The game features two modes: a free endless mode that allows for unrestricted exploration and a competitive mode where players can challenge AI corporations. This dual approach offers a variety of gameplay experiences, catering to different player preferences and strategies.

The DLC also includes a Space Station that serves as the central hub for managing planetary colonies and conducting interplanetary research. Players can utilize the new Orbital Space Lift to efficiently transport resources between colonies and the Space Station at no cost. Additionally, the introduction of extensions enhances city centers with unique abilities, allowing for tailored strategies in city development. An introductory story campaign provides context and engages players in the simulation's universe.