An endless runner-type game, Run 3 sees you playing as 'the runner', trying to find your way home through space tunnels. The runner is in constant forward motion and you must dodge left and right with the arrow keys to avoid falling off the path. You can also jump holes in the floor with spacebar. Moving to the sides of the path rotates the whole tunnel 90 degrees so the wall becomes the floor. The levels get more difficult as you go through the game and different characters are unlocked as you progress.
In addition to the Explore mode, there is an Infinite mode where the aim is simply to run for as long as possible.
The game is the third in the Run series. It was initially released for mobile devices titled just 'Run' due to it being the series' debut on Android. When later released for web browsers its full title 'Run 3' was used.