Robak (Worm) is a black-and-white Snake variant. The player controls a snake in a small room filled with fruits, obstacles and bonus elements. The goal is to eat the food while avoiding the obstacles (including one's own tail) to achieve the necessary length to open the door to the next stage. The player is limited by the amount of food. The worm must attain the sufficient length before supplies run out. Whenever the snake eats a piece of food, it grows longer, making it more difficult to maneuver. The snake moves forward at a constant speed and can be turned in the four cardinal directions. Encountered obstacles shorten the length of the worm. Fruit can rot and change into trees. Bonus elements add extra points.