Universe Sandbox is a simulation in which the player is able to create, manipulate and destroy various elements in the universe from planets to galaxies. Players have the option to explore pre-existing simulations (and manipulate variables or add objects if they so choose), or create their own simulations.

Running a simulation of our solar system, the player can add a rogue star and watch the aftermath as planets lose their orbits and collide with each other. Or they can change the orbit of planets, their masses and various other variables in order to change how the solar system functions. The player can also compare the size of everything in the solar system from moons to planets.

Some more fun/less serious elements of the game involve zero gravity pool, or creating a solar system made of out various sports balls. There is also an option to use 3D glasses to view the game, in order to add a 3D element to the game.

The game is now in Legacy, with no further updates from the development team, and has been replaced with Universe Sandbox ².