The game is based around a portal that can transport send one ship at a time. The goal for each player is to protect your portal, and to destroy all other portals in the game. As the player, you can choose to receive any of the following three ship types to be send through next:

As you might have guessed at this point, rock ships defeat scissors ships, scissors ships defeat paper ships and paper ships defeat rock ships. Easy as pie!
So are these really the only units in the game? Well yes! But to make things slightly more interesting, it is possible to make use of the environment in the form of meteors. You can occupy meteors using ships, making them a larger, more powerful but very slow fourth unit.