D209

Designed by Dries De Clercq, this one assembled by J. A. Storer 2013.
(cardboard sleeve, metal tray, and 10 plastic pieces, 3.8 x 3.1 x 5/16 inches)

Here is the start position and every position in which the 2x2 piece moves, along with steps 38, 50, 135, 154, and 164 (added to fill in longer gaps) of a solution of 209 rectilinear moves (using 241 straight-lines moves, although 238 straight-line moves are possible):