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The Half Hour puzzle is Stewart Coffin's #29 on his extensive list of more than 200 original designs. It was designed in 1980 and it was Stewart's (successful) attempt at creating a Soma-type cube with a unique solution. 

The copy I have for review today, is made by Puzzle Crafthouse, all made with wood with the cover measuring about 7,5cm (approx. 3").

There are a couple of key differences between the Half Hour and the Soma Cube. What they do have in common is that they're both 3x3x3 cubic dissections. 

- The first difference is that the Half Hour has six pieces instead of seven, all dissimilar. The Soma Cube had two similar pieces, but they were mirror images from each other.

- The Half Hour has only one unique solution and the Soma Cube has 240.

These differences are what makes the Half Hour puzzle so interesting. The name comes from the fact that Stewart thought half an hour was a good time to solve the puzzle.

As the puzzle has this very unique particularity with its name, I was actually curious to know the time it would take me to solve it and so, I timed my first attempt (about two weeks ago)... Well, it didn't take me exactly 30 minutes or less, but 36 minutes can't be that bad, can it? I was surprised to solve it so close to the actual 30 minutes, so I guess Stewart was absolutely right when he said that. My second attempt, just before writing this review was about 12 minutes. Probably the first attempt was still fresh in my mind, though, as I remembered how certain pieces should be placed...

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You might be asking yourself, how does the Half Hour puzzle compare in difficulty, to the Soma Cube? Is it more difficult just because it has only one solution, or the fact that it has so many placement restrictions for a given piece, makes it even easier? - In fact, I can answer those questions, because I have a Soma Cube in my collection and gave it a try, to see how long it took me to find one of the 240 solutions. Answer: 2 minutes! I guess it's clear which one is harder...

Closing Comments:

Puzzle Crafthouse's own version of the Half Hour puzzle is definitely worth a look. The puzzle is very well made and contrary to what I thought it was, what appears to be the lid, is meant to be the actual base for solving the puzzle and the longer part is the cover. For what you get, the price is also very affordable at $16 USD.

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