Huestack: The Tube Trials

Sort the balls in the tubes. To finish a level the tubes have to be filled to the top with only identically colored balls or be empty. Use the letter keys to pick a ball and place it into another tube. You can also put the ball back into the same tube. When moving a ball to another tube you can only drop it on top of an equally colored ball or into an empty tube. Invalid moves are blocked and indicated by a flashing border. There is not time or retry limit. Progress is saved after solving a level.