For those of you that have issues with the sliding puzzle at chapter 3, here is the solution:
First make sure that the puzzle is reset (leave and enter the puzzle to do so). Then move the blocks accordingly:
Left, Down, Right, Up, Right, Down, Down, Left, Up, Right, Up, Left, Down, Right, Down, Left, Left, Up, Up, Right, Down, Down, Left, Up, Right, Right, Up, Left...
And done!