Puzzles come in many forms, all shapes and sizes, but there’s probably no puzzle genre that offers more variety and range in difficulty than mechanical brain teasers.

The physical element adds so much to the solving experience that cannot be replicated in other puzzle styles. Whether you’re assembling pieces into a given shape, manipulating two pieces to separate them (or put them together), or twisting and turning a puzzle until it becomes the desired shape, mechanical brain teasers offer a world of possibility.

And in today’s product review, we’ve got three different varieties of brain teaser to test out, all courtesy of the creative minds at Project Genius. All three are part of their True Genius line of wooden brain teasers, rated for ages 14 and up, and each has its own ranking on a scale of 1 to 5 in difficulty.

Without further ado, let’s get solving!

Our trilogy of puzzle styles begins with a 3-out-of-5-star difficulty brain teaser. To conquer Sword in Stone, you must live out the legend of an ancient knight who plunged his sword into a stone and must remove it from its new home.

The sword can move up or down depending on how you twist the hilt back and forth, hoping to outmaneuver a maze of different paths you cannot see. It’s a marvelous little puzzle where you have to build a model of its interior in your mind by process of elimination, turning the sword this way and that, lifting and lowering it in stages until it’s free.

[Yes, I’m posting this to prove I solved it.
But I’ve hidden the key’s details to prevent spoilers.]

You really do feel like a champion once you’ve made the final twist and the sword slips from its forever tomb. There’s a playful give-and-take between you and the brain teaser that encapsulates the patience, determination, and deductive skill necessary to be a strong puzzler.

But then, once you’re completed the Herculean task, you have to put it back into place. And despite the fact that you’ve literally just performed the last few steps, doing them in reverse and returning the blade to the stone is even harder.

I thoroughly enjoyed tackling his mechanical puzzle. It hit the sweet spot of challenge and satisfaction without taking up too much solving time. It won’t take you 900 years to crack this one, but that doesn’t make it any less worthwhile.

For a more traditional jigsaw-style solving experience, you can try Cathedral Door, a 4-out-of-5-star difficulty brain teaser. Again, the challenge laid before you sounds simple: reassemble this beautiful door by placing all of the pieces of wooden adornment into the stained glass pattern.

Yes, this one even helps you place the wooden pieces by offering a color pattern to follow, with various shapes leaving outlines for you to complete with the many wooden jigsaw-style pieces.

Of course, these pieces are unique in shape and design, some of them squat and complex, others long, thin, and rangy. It’s amazing how many ways you can place these puzzle pieces that seem to fit the pattern to a tee. With seemingly infinite permutations, how will you ever put them all back?

And yet, when you place a piece properly, it immediately feels right. It’s a very curious solving sensation — knowing for sure that a piece FITS somewhere, even if the other pieces around it haven’t been placed yet — but it’s one that makes solving Cathedral Door a very engaging challenge. I didn’t find it all that much harder than Sword in Stone, so I’m not sure a full star in difficulty difference is warranted, but this remains an eye-catching and challenging puzzle.

We round out our trifecta of brain teasers by maxing out the difficulty scale with this 5-out-of-5-star-ranked mathematical puzzle, Grecian Computer, created as a spiritual successor of the Antikythera Mechanism. And undoubtedly, this puzzle might leave people just as baffled as the piece that inspired it.

You must spin and twist this wooden “computer” until the numbers in all twelve columns add up to 42 at the same time. That’s daunting in and of itself. But it’s more than just spinning various dials.

There are cut-outs in some wheels where the numbers below can be shown, flaps that block other numbers, and joined pieces that spin together. Each of the four wheels — plus the base — have numbers at all 12 clock positions, and even a small rotation can vastly change the arrangement of numbers in front of you.

It genuinely feels like the mathematical equivalent of a Rubik’s Cube, each twist bringing one column to completion while leaving others further than ever from a unified solution. There are a lot of variables at play here, and it can be a little frustrating.

And yet, you never despair. You never feel like giving up. Each small victory, each alignment that makes sense in your head, inches you closer, and before long, you’re spinning and twisting like a dervish, eliminating false paths and unhelpful combinations en route to victory.

This brain teaser most definitely deserves the 5-out-of-5 difficulty rating, and it’s also beautifully engineered. The bottom wheel spins at the barest touch, and while others have more resistance, you can’t help but marvel at this well-made and devious machine.

Sword in Stone, Cathedral Door, and Grecian Computer are all available through Project Genius as well as certain online retailers.

Whether you’re looking for a deduction puzzle, an assembly puzzle, or a twisty puzzle, one of these impressive brain teasers from Project Genius is sure to hit the spot. And all three are part of this year’s Holiday Puzzly Gift Guide, coming soon, so be sure to check it out!

[Note: I received a free copy of each brain teaser in exchange for a fair, unbiased review. Due diligence, full disclosure, and all that.]

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