Hi iMaterialise fans,
Turn Four is based on an idea by Sjaak Griffioen. Sjaak wanted nine squares in a 3x3 grid, where any combination of 2x2 could be rotated by multiples of 90 degrees. Wim Zwaan built him a wooden prototype where one could lift out four square with your fingers. Whereas the puzzle worked, it was very easy to cheat by flipping the puzzle over and place the pieces. This version is more of a classic twisty puzzle with no cheating possibility.