Circle is a single-player, keyboard-controlled game. It has two distinct parts. It starts in a room represented by shaky white lines. In that room is a circle also represented by a white line. On the screen are four options: Go Out, Feeding, Loving and Killing.
- The Feeding option naturally feeds the circle which grows a little larger as a result.
- The Go Out option is used when the player leaves the room to get food.
- The Loving option allows the player to stroke or praise the circle which makes it happy.
- Finally there is the Killing option which ends the game
When the player goes outside the game changes from a first-person view to a 2D-scrolling bird’s-eye view as the player negotiates narrow maze-like pathways in search of food. The search for food is a timed event; a countdown clock is shown in the upper left of the screen.
The game has no score and no dialogue. It plays in a window with no fullscreen option and it has music.
