I cheated (by modifying the source code to allow infinite jumps) to get to the highest part of the top room after the physics wouldn't allow me to stack the tables high enough (they kept resetting and dropping down). Also a few bugs had me falling through the floor on the top level which made trying to stack them frustrating. I also had to look at your pictures to understand where I was supposed to take the items as it didn't actually say checkout which would have helped.