the ice block is pretty paradoxical to me.
long distance move, single tile move -> paradox (the ice should have slid on the first turn.
yes, there are some levels which could not have been beaten in reverse
I believe the ice block should only unslide once if pulled in the same direction, and must have a sensible blockade (at least one on its left or right) to be coherent when played unreversed.
Yup, I'll need to adjust them if I want to make them logical
