“Rainbow tube:color sorting” is a color sorting game in which the player needs to correctly sort colored liquids into glass tubes, making sure that the colors are not repeated in all tubes. As the level of the game increases, so does the difficulty and may require players to use critical thinking skills to win the game. Players move the top liquid to another tube by clicking on the tube, but only when the tops of both tubes are the same color. If the player encounters difficulties, props can be used to help solve the problem.