When the player or a box is clicked the reachable squares are now shown with a little circle graphic.
The player can now "go through" boxes that can be pushed away and then back to the original position for reaching the actual box to be pushed.
A white circle indicates reachable positions that can be reached without the go through feature.
A dark square indicates positions that are only reachable when pushing boxes due to the go through feature.
The boxes that can be used to "go through" are marked with a black circle.
Using this feature it's possible to select a box for pushing that can only be pushed when going through other boxes by pushing them first away and the back to the original position.