Snake is a video game that came out in the mid-to-late 1970s. It gained popularity in the 1990s for its inclusion on some mobile phones. The player controls a long, thin creature, resembling a snake, which roams around on a bordered plane, picking up food (or some other such item), trying to avoid hitting its own tail or the "walls" that surround the playing area. Each time the snake eats a piece of food, its tail grows longer, making the game increasingly difficult. The user controls the direction of the snake's head (up, down, left, or right), and the snake's body follows. The player cannot stop the snake from moving while the game is in progress. The simplicity of the game is what makes the game ideal for mobile phones.