In Race the Sun you control a spaceship powered by solar energy. You have to dodge objects on your way, for example, from laser beams, other ships and various obstacles, while collecting blue pyramids that will boost the player. The game will end only when you either crash into something, die, or when the sun goes down. The ship's speed remains constant until the ship remains under direct sunlight, but if the ship falls into shadow or collides with an object, the ship's speed will drop.

You have to fly through the landscape with abstract shapes and obstacles of varying complexity. Levels are procedurally generated and divided into separate regions, and each contains its own set of tests.

The game presents three primary levels: the standard level, the level of "Apocalypse", in which the player moves faster through more difficult tests, and an obstacle course in the form of a maze. These regions and levels change daily for all players, and the online scoreboard allows users to compare their results with others.