This unusually shaped, and yet fascinating puzzle is called Monroe's Marbles, invented by Donald Monroe Jr. in 2004 and manufactured by Dionny Inc.

Monroe's Marbles has twenty-eight marbles in four colors and four acrylic tubes. An opaque square tube connects the vertical tubes allowing the marbles to be transferred from one tube to another. If you look closely, you'll see that the acrylic tubes aren't exactly vertical, but more like with a subtle inclination angle, which makes it easier to get the marbles out of them. The goal is to get seven marbles in each of the four tubes so that they show a specific pattern, e.g., same color marbles for each tube.

At first sight, the puzzle looks like just a child's toy, but there's much more to it than it shows. As the name suggests, the balls are actually colored marbles, not plastic balls, and this is noticeable by the sound of them colliding with each other. It's also quite a big puzzle, measuring about 17.5cm in height and 14.5cm in length (top) (about 7" x 5.7").

(Click to Enlarge) - Scrambled

A great thing when ordering the puzzle is that you can choose the color combination you want for the opaque tube and base. There are four colors to choose from: blue, red, yellow and green (same colors as the marbles). The opaque tube can have one or two colors, giving the entire puzzle a combo of two or three different colors. For me, I chose two combinations for two puzzles: blue-yellow tube and blue base; red-green tube and blue base.

Solving the Monroe's Marbles looks harder than it actually is. Getting any of the desired color patterns takes no more than 10 minutes or so. It is a sequential movement puzzle, so it only requires a bit of concentration. The puzzle comes with instructions and a scoring table: One Tube -> Beginner; Two/Three Tubes -> Intermediate; Four Tubes -> Expert; Four Tubes w/ Color Pattern -> Genius. I reckon that if you solve one tube, you won't have problems with the others, as they're not that much harder. Just take a little more time, because you have to move one marble at a time.

(Click to Enlarge) - Four Color Sequence & Alternating Color Patterns

To get the puzzle scrambled, all you need to do is hold it upside down while holding the base. Then, shake it until all marbles disappear into the opaque tube and turn it over again. After having the puzzle well scrambled, choose a color pattern and solve it. You'll notice that the acrylic tubes are longer than the seven marble length, so take advantage of this. Each tube can hold up to eleven marbles, although if you fill it entirely, there's not enough space to let another marble pass through that tube. The ideal number is ten marbles per tube.

Getting a desired marble from one tube to another may be a little frustrating at first, but there's a simple trick to do that. Just hold the puzzle at an angle with the tube that holds the marble you want to move, facing the floor. With a gentle move, the marble will roll down the acrylic tube into the opaque one and then, just tilt the puzzle until it reaches the tube you want to place it. Repeat until solved.

Closing Comments:

Solving the Monroe's Marbles is quite fun, although it's far from challenging and it can be a little repetitive if you attempt to solve multiple challenges one after another, but ultimately, that's what sequential movement puzzles feel like. You just have to be patient with them. Be thankful it doesn't require 1000+ movements like some of the more complex in this category.

Availability: The Monroe's Marbles are available directly from the official website at $12 USD per puzzle. Multiple purchases have discount. Also, feel free to choose your own color combo, as you won't be charged for that.