Kevin Sadler wrote about it:

“I started with this delightful puzzle by the master of sliding-move puzzles. I already own this one made from acrylic but the wooden one looks so much more lovely. Pelikan have constructed this one from Garapa, Bubinga and Oak with wonderfully contrasting colours and a stunningly finished tray to pack the pieces into. There are 4 identical stepped pieces and a cross to fit inside the tray with the challenge being made by the fact that there is a considerable lip covering the tray making insertion of more than 3 pieces quite challenging. It is fairly easy to work out several possible square(ish) assemblies that might fit when playing outside the tray but getting them into the tray quickly gets quite confusing. The temptation is to try and squeeze one of the pieces diagonally under the lip of the tray but don’t bother – that requires force and is the wrong way to do it.

The first time I worked on it, the solution took me a good hour or so to solve and tha