Dinosaur Egg

The name of this puzzle, originally in Japanese, "Kyoryu No Tamago" translated means "Is It A Dinosaur Egg?". Its from Japanese designer Minoru Abe, renowned for his colourful, cute, whimsical and many very challenging sliding block puzzles. This one is no different and was designed 28 years ago, one of his earliest. The Dinosaur Egg today is rather hard to find (no pun intended) and I was very lucky to get my copy courtesy of my puzzling friend, Frederic Boucher who lives in Japan.

START

The object is to slide the pieces within the irregular shaped tray, (rectilinear moves only) from the given START position to the FINISH, which resembles a (dinosaur) egg. There are four pieces each piece forming a quarter of the egg. Three of the pieces have notches which are able to interact with the protrusions within the tray.

The instructions are in Japanese but the accompanying diagrams are pretty clear on what must be done. Frederic did a bit of the translation for me - the solution requires 22 moves. 

FINISH

I played with Dinosaur Egg for a good hour and after getting stuck and resetting the puzzle at least a half dozen times, I managed to reach the end stage. I am not sure if the 22-moves solution is "unique" though? Meaning that you need to get the sequence correct right from beginning to the end or you will invariably get stuck in the middle and have to back-track to the last correct position. Or could more moves be taken and still reach the end?

Only four pieces, but a unique and interesting idea for a sliding block design, and challenging too!

There appears to be very little information about Minoru Abe, the man himself. But check out Holt Davey's FaceBook page here about Abe.