This was a really fun game! I enjoyed passing around the boxes to get to the truck! I noticed that other people have already told you about the wall friction, so I have another suggestion for future games like this: input buffering. It can be annoying if you click a little early or late and miss the box completely, so giving like a 0.2 second window can really do a lot. I'm not sure if the game already has this or not but there were a few times when I felt like the click should have picked up the box but it didn't and input buffering is usually a good fix to that.