Tube Master at Cool Math Games: Lay pipes between pipe connections of the same color. The pipes aren't allowed to cross, and you'll need to fill all of the. If you like tricky puzzles, Glow Lines is the perfect game for you. Your goal is to connect matching colors. Pair all colors and cover the entire board. Only with. Flow Free® is a simple yet addictive puzzle game. Connect matching colors with pipe to create a Flow ®. Pair all colors, and cover the entire board to solve each.