Google finally brought its popular sci-fi-inspired augmented-reality game Ingress to iOS Monday, July 14, nearly two years after the game first launched on Android.

This is particularly notable since augmented reality-style mobile games tend to be more popular on Android than on iOS, Mashable reports.

Ingress is about the discovery of a new controversial "mysterious energy." The game pits the "Enlightened" (those who want to use the energy to evolve humanity) against the "Resistance" (those who want to protect humankind from it).

Players begin by choosing a side, and then join thousands of other users to collectively bring victory to their team.

Ingress uses players' actual location for gameplay: To advance in the game, they must walk around and explore their neighborhood IRL. Matter is hidden in places around a player's neighborhood, for example, while parks, landmarks and other public venues become "portals," which are locations that individual players can strategically take over and control.

Ingress is a project of Google's Niantic Labs, the same team behind the Field Trip apps for iOS, Android and Google Glass, which also rely on augmented reality for local discovery.

The game officially launched on Android last December, more than a year after its beta version first came out. The latest version of Ingress has cross-platform compatibility, so Android and iOS users can compete against each other.