Puzzleguru. I bought this one because it looked nice and I wanted something from this particular puzzle designer for my collection. It also should be quite a lot easier than the cast spiral - it is rated as 3 out of a possible 6.
It was originally designed by the extremely prolific Dutch puzzle designer Oskar van Deventer. To get an idea about his talents view his designs at Shapeways - take special note of the $2000 17x17x17 Rubik's cube! The original design did not have a definite starting position and so for the Hanayama version the two eyes were placed to ensure the puzzler always started and finished at the correct point.
As with all Hanayama designs, the puzzle is well packaged and when taken out of the box the first thing that strikes you is the beauty of the puzzle - it is a white and yellow metal and very well finished. Movement of the inner piece (the traveller) is limited by a tapered bar on it's surface which only allows the piece to move to areas with a corresponding notch cut into them. It cannot pass all the way through the notch because the notch is too small to allow full passage of the central bulge in the bar. The aim is to separate the 2 pieces by moving the gold coloured traveller back and forth, effectively through the maze of notches.
website. He has worked out how to do it in 8 moves! It is a lovely piece of analysis.
Overall this is a nice puzzle and satisfying to fiddle with. It is not particularly difficult. I do prefer the cast spiral because of its apparent simplicity. I have decided that straight-forward maze type puzzles are not my favourite. I have my eye on some other Hanayama puzzles and will report back when I get them.