Karu is a Match 3 game wherein the player's task is to remove a giant snake by removing its marbles. In this game, a giant snake composed of colored marbles moves around a certain path in the game screen. The player catches colored balls from the sky. When colored balls are caught, only then can the balls be fired at the moving snake. If the fired ball lands on that part of the snake with similar colored balls, those colored balls are removed. If the fired colored ball lands on that part of snake with different colors, the ball just adds to the snake's length. If the colored ball from the sky that is not caught lands on the snake, it also adds to the snake's length. If the ball falls off the game screen, the snake moves forward in a rapid speed.
Karu has 89 stages. After each stage, the snake moves faster. The balls that are dropping from the sky also increase. The number of colored balls increase as well. The game features 11 power-ups that can affect the snake's movements. After every 5 stages, a bonus round can be played. Also, a puzzle is presented to the player at the start of the 80th level.