The puzzle is made of three spiral entangled pieces, all different from each other, and you have to disentangled them with a specific order.

Well, this is the most difficult puzzle from Hanayama that I've tried so far. As of now, I'm yet to completely disassemble the three pieces, having them with the ends still entangled. When you first look at the puzzle, the way that the pieces are entangled, resemble the Cast Coaster, which is also made with three parts. Disentangling the first part is not that hard: you just need to loosen the pieces one at a time until they all move freely (not that much), but still entangled. The problems start when you try to separate a piece from the trio, something I'm still struggling with. I see grooves on each piece, meaning that you need to combine or pass one of the ends of a piece to one of these grooves, although I can't seem to find an exact combination for the right groove with the right end-piece. 

Now, I could've just looked at the solution and write a completely different review, but stubborn as I am, I'm  going to keep trying until I solve it. I have been trying this puzzle for about two weeks now, a little bit each day, though the longest I've spent with a Cast Puzzle is over a month, with the Cast Elk.

The Vortex is rated by Hanayama as a 5 out of 6 level and a 9 out of 10 by PuzzleMaster, but unless I'm missing something, this has to be top difficulty in both scales, for the time it takes to separate the pieces and the level of complexity applied to the concept.

I really recommend this puzzle if you like a really tough mind boggling challenge. I think it's clear that it's not one of those puzzles you solve in minutes, so you'll have in hands something to entertain you for days, unless you lose your patience before that... If you do lose your patience, you can always try to solve it with the help of a solution sheet.

As of the time of writing this review, PuzzleMaster has the Cast Vortex sold out, but if you're really interested in buying one, check back their site often, because they restock frequently.